With this verse this Psalm beginneth.
2. "The Lord said unto my Lord, Sit Thou on My right hand, until I make Thine enemies Thy footstool" (ver.1). We ought, therefore, thoroughly to consider this question proposed to the Jews by the Lord, in the very commencement of the Psalm. For if what the .Jews answered be asked of us, whether we confess or deny it; God forbid that we should deny it. If it be said to us, Is Christ the Son of David, or not? if we reply, No, we contradict the Gospel for the Gospel of St. Matthew thus beginneth, "The book of the generation of Jesus Christ, the Son of David."  The Evangelist declareth, that he is writing the book of the generation of Jesus Christ, the Son of David. The Jews, then, when questioned by Christ, whose Son they believed Christ to be, rightly answered, the Son of David. The Gospel agreeth with their answer. Not only the suspicion of the Jews, but the faith of Christians, doth declare this...."If then David in the spirit called Him Lord, how is He his son?" The Jews were silent at this question: they found no further reply: yet they did not seek Him as the Lord, for they did not acknowledge Him to be Himself that Son of David. But let us, brethren, both believe and declare: for, "with the heart we believe unto righteousness: but with the mouth confession is made unto salvation;"  let us believe, I say, and let us declare both the Son of David, and the Lord of David. Let us not be ashamed of the Son of David, lest we find the Lord of David angry with us.
3. ...We know that Christ sitteth at the right hand of the Father, since His resurrection from the dead, and ascent into heaven. It is already done: we saw not it, but we have believed it: we have read it in the Scripture, have heard it preached, and hold it by faith. So that by the very circumstance that Christ was David's Son, He became His Lord also. For That which was born of the seed of David was so honoured, that It was also the Lord of David. Thou wonderest at this, as if the same did not happen in human affairs. For if it should happen, that the son of any private person be made a king, will he not be his father's lord? What is yet more wonderful may happen, not only that the son of a private person, by being made a king, may become his father's lord; but that the son of a layman, by being made a Bishop, may become his father's father. So that in this very circumstance, that Christ took upon Him the flesh, that He died in the flesh, that He rose again in the same flesh, that in the same He ascended into Heaven, and sitteth on the right hand of His Father, in this same flesh so honoured, so brightened, so changed into a heavenly garb, He is both David's Son, and David's Lord....
4. Christ, therefore, sitteth at the right hand of God, the Son is on the right hand of the Father, hidden from us. Let us believe. Two things are here said: that God said, "Sit Thou on My right hand;" and added, "until I make Thy enemies Thy footstool;" that is, beneath Thy feet. Thou dost not see Christ sitting at the right hand of the Father: yet thou canst see this, how His enemies are made His footstool. While the latter is fulfilled openly, believe the former to be fulfilled secretly. What enemies are made His footstool? Those to whom imagining vain things it is said, "Why do the heathen so furiously rage together: and why do the people imagine a vain thing?" etc.  ...He therefore sitteth at the right hand of God, till His enemies be placed beneath His feet. This is going on, this is taking place: although it is accomplished by degrees, it is going on without end. For though the heathen rage, will they, taking counsel together against Christ, prevent the fulfilment of these words: "I will give thee the heathen for thine inheritance, and the utmost parts of the earth for thy possession"?..."Their memorial is perished with a cry;" but, "The Lord shall endure for ever:"  as another Psalm, but not another Spirit, saith.
5. And what followeth? "The Lord shall send the rod of Thy power out of Sion" (ver.2). It appeareth, brethren, it most clearly appeareth, that the Prophet is not speaking of that kingdom of Christ, in which He reigneth for ever with His Father, Ruler of the things which are made through Him: for when doth not God the Word reign, who is in the beginning with God?  For it is said, "Now unto the King eternal, immortal, invisible, the only wise God, be honour and glory for ever and ever."  To what eternal King? To one invisible, incorruptible. For in this, that Christ is with the Father, invisible and incorruptible, because He is His Word, and His Power, and His Wisdom, and God with God, through whom all things were made; He is "King eternal;" but, nevertheless, that reign of temporal government, by which, through the mediation of His flesh, He called us into eternity, beginneth with Christians; but of His reign there shall be no end. His enemies therefore are made His footstool, while He is sitting on the right hand of His Father, as it is written; this is now going on, this will go on unto the end....
6. When therefore He hath sent the rod of His power out of Sion: what shall happen? "Be Thou ruler, even in the midst among Thine enemies." First, "Be Thou ruler in the midst of Thine enemies:" in the midst of the raging heathen. For shall He rule "in the midst of His enemies" at a later season, when the Saints have received their reward, and the ungodly their condemnation? And what wonder if He shall then rule, when the righteous reign with Him for ever, and the ungodly burn with eternal punishments? What wonder, if He shall then? Now "in the midst of Thine enemies," now in this transition of ages, in this propagation and succession of human mortality, now while the torrent of time is gliding by, unto this is the rod of Thy power sent out of Sion, "that Thou mayest be Ruler in the midst of Thine enemies." Rule Thou, rule among Pagans, Jews, heretics, false brethren. Rule Thou, rule, O Son of David, Lord of David, rule in the midst of Pagans, Jews, heretics, false brethren. "Be Thou Ruler in the midst of Thine enemies." We understand not this verse aright, if we do not see that it is already going on....
7. "With Thee the beginning on the day of Thy power" (ver.3). What is this day of His power, when is there beginning with Him, or what beginning, or in what sense is there beginning with Him, since He is the Beginning?...
8. What meaneth, "With Thee is the beginning"? Suppose anything you please as the beginning. Of Christ Himself, it would rather have been said, Thou art the Beginning, than, With Thee is the beginning. For He answered to those who asked Him, "Who art Thou?" and said, "Even the same that I said unto you, the Beginning;"  since His Father also is the Beginning, of whom is the only-begotten Son, in which Beginning was the Word, for the Word was with God. What then, if both the Father and the Son are the beginning, are there two beginnings? God forbid! For as the Father is God, and the Son is God, but the Father and the Son are not two Gods, but one God: so is the Father Beginning and the Son Beginning, but the Father and the Son are not two, but one Beginning. "With Thee is the beginning." Then it shall appear in what sense the beginning is with Thee. Not that the beginning is not with Thee here also. For hast Thou not also said, "Behold, ye shall be scattered, every man to his own, and shall leave Me alone; but I am not alone, because the Father is with Me"?  Here therefore also, the beginning is with Thee. For Thou hast said elsewhere also, "But the Father that dwelleth in Me, He doeth His works."  "With Thee is the beginning:" nor was the Father ever separated from Thee. But when the Beginning shall appear to be with Thee, then shall it be manifest unto all who are made like Thee; since they shall see Thee as Thou art;  for Philip saw Thee here, and sought the Father.  Then therefore shall be seen what now is believed: then shall "the beginning be with Thee" in the sight of the righteous, in the sight of saints; the ungodly being removed, that they may not see the brightness of the Lord....
9. Explain of what power thou speakest. Because here also, as is said, His power is mentioned, when the rod of His power is sent forth out of Sion, that He may be Ruler in the midst of His enemies. Of what power speakest thou, "In the splendour of the saints"? "In the splendour," he saith, "of the saints." He speaketh of that power when the saints shall be in splendour; not when still carrying about their earthly flesh, and groaning in a mortal and corruptible body....
10. But this is put off, this will be granted afterwards: what is there now? "From the womb I have begotten Thee, before the morning star." What is here? If God hath a Son, hath He also a womb? Like fleshly bodies, He hath not; for He hath not a bosom either; yet it is said, "He who is in the bosom of the Father, hath declared Him."  But that which is the womb, is the bosom also: both bosom and womb are put for a secret place. What meaneth, "from the womb"? From what is secret, from what is hidden; from Myself, from My substance; this is the meaning of "from the womb;" for, "Who shall declare His generation?"  Let us then understand the Father saying unto the Son, "From My womb before the morning star have I brought Thee forth." What then meaneth, "before the morning star"? The morning star is put for the stars, as if the Scripture signified the whole from a part, and from one conspicuous star all the stars. But how were those stars created? "That they may be for signs, and for seasons, and for days, and years."  ...This expression also, "before the morning star," is used both figuratively and literally, and was thus fulfilled. For the Lord was born at night from the womb of the Virgin Mary; the testimony of the shepherds doth assert this, who were "keeping watch over their flock."  So David: O Thou, my Lord, who sittest at the right hand of my Lord, whence art Thou my Son, except because, "From the womb before the morning star I have begotten Thee"?
11. And unto what art Thou born? "The Lord hath sworn, and will not repent: Thou art a Priest for ever after the order of Melchizedec" (ver.4). For unto this wast Thou born from the womb before the morning star, that Thou mightest be a Priest for ever after the order of Melchizedec. For in that character in which He was born of the Father, God with God, coeternal with Him who begot Him, He is not a Priest; but He is a Priest on account of the flesh which He assumed, on account of the victim which He was to offer for us received from us. "The Lord," then, "hath sworn." What then meaneth, the Lord hath sworn? Doth the Lord, who forbiddeth men to swear,  Himself swear? Or doth He possibly forbid man to swear chiefly on this account, that he may not fall into perjury, and for this reason the Lord may swear, since He cannot be forsworn. For man, who, through a habit of swearing, may slip into perjury, is rightly forbidden to swear: for he will be farther from perjury in proportion as he is far from swearing. For the man who sweareth, may swear truly or falsely: but he who sweareth not, cannot swear falsely; for he sweareth not at all. Why then should not the Lord swear, since the Lord's oath is the seal of the promise? Let Him swear by all means. What then dost thou, when thou swearest? Thou callest God to witness: this is to swear, to call God to witness; and for this reason there must be anxiety, that thou mayest not call God to witness anything false. If therefore thou by an oath dost call God to witness, why then should not God also call Himself to witness with an oath? "I live, saith the Lord," this is the Lord's oath...."The Lord sware," then, that is, confirmed: "He will not repent," He will not change. What? "Thou art a Priest for ever. "For ever," for He will not repent. But Priest, in what sense? Will there be those victims, victims offered by the Patriarchs, altars of blood, and tabernacle, and those sacred emblems of the Old Covenant? God forbid! These things are already abolished; the temple being destroyed, that priesthood taken away, their victim and their sacrifice having alike disappeared, not even the Jews have these things. They see that the priesthood after the order of Aaron hath already perished, and they do not recognise the Priesthood after the order of Melchizedec. I speak unto believers. If catechumens understand not something, let them lay aside sloth, and hasten unto knowledge. It is not therefore needful for me to disclose mysteries here:  let the Scriptures intimate to you what is the Priesthood after the order of Melchizedec.
12. "The Lord on Thy right hand" (ver.5). The Lord had said, "Sit Thou on My right hand;" now the Lord is on His right hand, as if they changed seats....That very Christ, the "Lord on Thy right hand," unto whom Thou hast sworn, and it will not repent Thee: what doth He, Priest for evermore? What doth He, who is at the right hand of God, and intercedeth for us,  like a priest entering into the inner places, and into the holy of holies, into the mysteries of heaven, He alone being without sin, and therefore easily purifying from sins.  He therefore "on Thy right hand shall wound even kings in the day of His wrath." What kings, dost thou ask? Hast thou forgotten? "The kings of the earth stood up, and the rulers took counsel together against the Lord, and against His Anointed."  These kings He wounded by His glory, and by the weight of His Name made kings weak, so that they had not power to effect what they wished. For they strove amain to blot out the Christian name from the earth, and could not; for "Whosoever shall fall on this stone shall be broken."  Kings therefore fall on this "stone of offence," and are therefore wounded, when they say, Who is Christ? I know not what Jew or what Galilean He may have been, who died, who was slain in such a manner! The stone is before thy feet, lying, so to speak, mean and humble: therefore by scorning thou dost stumble, by stumbling thou fallest, by falling thou art wounded...."But on whomsoever it shall fall, it will grind him to powder."  When therefore any one falleth upon it, it lieth as it were low; it then woundeth: but when it shall grind him to powder, then it will come from above. See how in these two words, it shall wound him and grind him to powder: he striketh upon it, and it shall come down upon him: are distinguished the two seasons, of the humiliation and the majesty of Christ, of hidden punishment and future judgment. He will not crush, when He cometh, that man whom He doth not wound when He lieth in a contemptible appearance....
13. "He shall judge among the heathen: He shall fill up what hath fallen" (ver.6). Whoever thou art who art obstinate against Christ, thou hast raised on high a tower that must fall. It is good that thou shouldest cast thyself down, become humble, throw thyself at the feet of Him who sitteth on the right hand of the Father, that in thee a ruin may be made to be built up. For if thou abidest in thy evil height, thou shalt be cast down when thou canst not be built up. For of such the Scripture saith in another passage: "Therefore shall He break down, and not build them up."  Beyond doubt he would not say this of some, unless there were some whom He broke down so as to build them up again. And this is going on at this time, while Christ is judging among the heathen in such a manner as to fill up what hath fallen. "He shall smite many heads over the earth." Here upon the earth in this life He shall smite many heads. He maketh them humble instead of proud; and I dare to say, my brethren, that it is more profitable to walk here humbly with the head wounded, than with the head erect to fall into the judgment of eternal death. He will smite many heads when he causeth them to fall, but He will fill them up and build them up again.
14. "He shall drink of the brook  in the way, therefore shall he lift up his head" (ver.7). Let us consider Him drinking of the brook in the way: first of all, what is the brook? the onward flow of human mortality: for as a brook is gathered together by the rain, overflows, roars, runs, and by running runs down, that is, finishes its course; so is all this course of mortality. Men are born, they live, they die, and when some die others are born, and when they die others are born, they succeed, they flock together, they depart and will not remain. What is held fast here? what doth not run? what is not on its way to the abyss as if it was gathered together from rain? For as a river suddenly drawn together from rain from the drops of showers runneth into the sea, and is seen no more, nor was it seen before it was collected from the rain; so this hidden rain is collected together from hidden sources, and floweth on; at death again it travelleth where it is hidden: this intermediate state soundeth and passeth away. Of this brook He drinketh, He hath not disdained to drink of this brook; for to drink of this brook was to Him to be born and to die. What this brook hath, is birth and death; Christ assumed this, He was born, He died. "Therefore hath He lifted up His head;" that is, because He was humble, and "became obedient unto death, even the death of the Cross: therefore God also hath highly exalted Him, and given Him a Name which is above every name; that at the Name of Jesus every knee shall bow, of things in Heaven, and things in earth, and things under the earth; and that every tongue shall confess that Jesus Christ the Lord is in the glory of God the Father." 
 Lat. CIX. A sermon to the people.  Matthew 22:42-45.  Matthew 1:1.  Romans 10:10.  Psalm 2:1, etc.  Psalm 9:7.  John 1:1.  1 Timothy 1:17.  John 8:25.  John 16:32.  John 14:10.  1 John 3:2.  John 14:8.  John 1:18.  Isaiah 53:8.  Genesis 1:14.  Luke 2:7, 8.  Matthew 5:34.  [He says elsewhere on Psalm 104.ver. 3: "What is that which is hidden, and is not public in the Church? The Sacrament of Baptism, the Sacrament of the Eucharist. For our good works even Pagans see, but Sacraments are hidden from them." Note the implications: two Sacraments, and no public celebration of the Eucharist. See A.N.F. vol. viii. Primitive Liturgies passim.--C.]  Romans 8:34.  Hebrews 9:12, 14, 24.  Psalm 2:2.  Matthew 21:44.  Luke 20:18.  Psalm 28:5.  De torrente.  Philip. ii. 8-11.
 Matthew 22:42-45.
 Matthew 1:1.
 Romans 10:10.
 Psalm 2:1, etc.
 Psalm 9:7.
 John 1:1.
 1 Timothy 1:17.
 John 8:25.
 John 16:32.
 John 14:10.
 1 John 3:2.
 John 14:8.
 John 1:18.
 Isaiah 53:8.
 Genesis 1:14.
 Luke 2:7, 8.
 Matthew 5:34.
 [He says elsewhere on Psalm 104.ver. 3: "What is that which is hidden, and is not public in the Church? The Sacrament of Baptism, the Sacrament of the Eucharist. For our good works even Pagans see, but Sacraments are hidden from them." Note the implications: two Sacraments, and no public celebration of the Eucharist. See A.N.F. vol. viii. Primitive Liturgies passim.--C.]
 Romans 8:34.
 Hebrews 9:12, 14, 24.
 Psalm 2:2.
 Matthew 21:44.
 Luke 20:18.
 Psalm 28:5.
 De torrente.
 Philip. ii. 8-11.