Ellicott's Commentary for English Readers
There are no data for ascertaining either the author or the date of this psalm. The variety of the figures employed seems to indicate a general view of life and its possible perils. It may have been a time when both war and pestilence were raging, but we cannot recover it. Whoever first breathed these words of trust, thousands have found them a source of strength and faith in the hour of trial and danger. Stier mentions that some years ago an eminent physician in St. Petersburg recommended this psalm as the best preservative against the cholera. It will also occur to every one that the psalm is the Hebrew, or, perhaps, rather the religious, expression of Horace’s ode,
“Integer vitæ seelerisque purus.”
The parallelism is fine and sustained.
He that dwelleth in the secret place of the most High shall abide under the shadow of the Almighty.(1, 2) He . . . I.—The especial difficulty of this psalm, its abrupt changes of person, meets us at the outset. The text literally rendered, runs: “He sitting in the hiding place of the Most High; In the shadow of the Almighty he lodgeth, I say to Jehovah, My refuge and my fortress, My God, I trust in Him. The change in the last clause presents no particular difficulty, as many similar instances occur; but that from the third person, in the first verse, to the first, in the second, is very awkward, and many shifts have been adopted to get out of it. The best is to supply the word blessed: “Blessed is he that,” &c The different names for God employed here should be noticed. By their accumulation the poet makes the sum of assurance doubly sure.
 The omission of this word by a copyist would be very natural, from its confusion with the numerical heading of the psalm and the initial letter of the word that now begins it.
Noisome pestilence.—Literally, pestilence of calamities, i.e., fatal. (See Psalm 57:1, where the same word “calamities” occurs.)
He shall cover thee with his feathers, and under his wings shalt thou trust: his truth shall be thy shield and buckler.(4) Feathers . . . wings . . .—For this beautiful figure, here elaborated, see Psalm 17:8, Note.
Thou shalt not be afraid for the terror by night; nor for the arrow that flieth by day;(5) Terror by night.—Possibly a night attack by an enemy. (Comp. Song of Solomon 3:8; Proverbs 3:23-26.) Comp. Milton:
“To bless the doors from nightly harm.”
In this case the arrow flying by day would refer to dangers of actual battle. But it is quite possible that the latter may be merely the Oriental expression for the pestilence, since it is still so called by Arabians. “I desired to remove to a less contagious air. I received from Solyman the emperor this message: that the emperor wondered what I meant in desiring to remove my habitation. Is not the pestilence God’s arrow, which will always hit his mark?”—Quoted in Spurgeon’s Treasury of David, from Busbequin’s Travels.
Nor for the pestilence that walketh in darkness; nor for the destruction that wasteth at noonday.(6) Darkness . . . noonday.—Night and noon are, in Oriental climates, the most unwholesome, the former from exhalations, the latter from the fierce heat.
Destruction.—From a root meaning “to cut off;” here, from parallelism, “deadly sickness.”
A thousand shall fall at thy side, and ten thousand at thy right hand; but it shall not come nigh thee.(7) It shall not come nigh thee.—It, i.e., no one of the dangers enumerated. The pious Israelite bears a charmed life. Safe under Divine protection, he only sees the effect of perils that pass by him harmless.
Because thou hast made the LORD, which is my refuge, even the most High, thy habitation;(9) Thou . . . my.—The difficulty of the change of person is avoided by the Authorised Version, but only with violence to the text, which runs, “For thou, Jehovah, my refuge; thou hast made the Most High thy habitation.” It is best to take the first line as a kind of under-soliloquy. The poet is assuring himself of the protection which will be afforded one who trusts in God; and he interrupts his soliloquy, as it were, with a comment upon it: “Yes, this is true of myself, for Thou Jehovah art indeed my refuge.” (For the Most High as a dwelling place, see Psalm 90:1.)
There shall no evil befall thee, neither shall any plague come nigh thy dwelling.(10) Dwelling.—Literally, tent: an instance in which the patriarchal life became stereotyped, so to speak, in the language. (See Note, Psalm 104:3.) Even we speak of “pitching our tent.”
For he shall give his angels charge over thee, to keep thee in all thy ways.(11) Angels.—The idea of a special guardian angel for each individual has possibly been favoured by this verse, though it had its origin in heathen belief:
“By every man, as he is born, there stands
A spirit good, a holy guide of life.”
Here, however, it is not one particular individual, but all who have fulfilled the conditions of Psalm 91:9-10 who are the objects of angelic charge. (Comp. Psalm 34:7.) (For the well-known quotation of this and Psalm 91:12 in the Temptation, see Matthew 4:6; Luke 4:10-11; with Notes in New Testament Commentary.)
They shall bear thee up in their hands, lest thou dash thy foot against a stone.(12) In their hands.—Literally, on, as a nurse a child. There is a Spanish proverb, expressive of great love and solicitude: “They carry him on the palms of their hands.”
Thou shalt tread upon the lion and adder: the young lion and the dragon shalt thou trample under feet.(13) Lion . . . adder . . . young lion.—These are used no doubt, emblematically for the various obstacles, difficulties, and danger which threatens life. (For “adder,” see Note, Psalm 58:4; “dragon,” Psalm 74:13.)
Because he hath set his love upon me, therefore will I deliver him: I will set him on high, because he hath known my name.(14-16) Another abrupt change of person. The conclusion of the psalm comes as a Divine confirmation of the psalmist’s expression of confidence. (Comp. Psalm 50:15; Psalm 50:23, with these verses.)
(14) Set his love upon me.—Or, clung to me