7:10-16 Man and wife must not separate for any other cause than what Christ allows. Divorce, at that time, was very common among both Jews and Gentiles, on very slight pretexts. Marriage is a Divine institution; and is an engagement for life, by God's appointment. We are bound, as much as in us lies, to live peaceably with all men, Ro 12:18, therefore to promote the peace and comfort of our nearest relatives, though unbelievers. It should be the labour and study of those who are married, to make each other as easy and happy as possible. Should a Christian desert a husband or wife, when there is opportunity to give the greatest proof of love? Stay, and labour heartily for the conversion of thy relative. In every state and relation the Lord has called us to peace; and every thing should be done to promote harmony, as far as truth and holiness will permit.

14. sanctified—Those inseparably connected with the people of God are hallowed thereby, so that the latter may retain the connection without impairing their own sanctity (compare 1Ti 4:5); nay, rather imparting to the former externally some degree of their own hallowed character, and so preparing the way for the unbeliever becoming at last sanctified inwardly by faith.

by … by—rather, "in … in"; that is, in virtue of the marriage tie between them.

by the husband—The oldest manuscripts read, "by the brother." It is the fact of the husband being a "brother," that is, a Christian, though the wife is not so, that sanctifies or hallows the union.

else … children unclean—that is, beyond the hallowed pale of God's people: in contrast to "holy," that is, all that is within the consecrated limits [Conybeare and Howson]. The phraseology accords with that of the Jews, who regarded the heathen as "unclean," and all of the elect nation as "holy," that is, partakers of the holy covenant. Children were included in the covenant, as God made it not only with Abraham, but with his "seed after" him (Ge 17:7). So the faith of one Christian parent gives to the children a near relationship to the Church, just as if both parents were Christians (compare Ro 11:16). Timothy, the bearer of this Epistle, is an instance in point (Ac 16:1). Paul appeals to the Corinthians as recognizing the principle, that the infants of heathen parents would not be admissible to Christian baptism, because there is no faith on the part of the parents; but where one parent is a believer, the children are regarded as not aliens from, but admissible even in infancy as sharers in, the Christian covenant: for the Church presumes that the believing parent will rear the child in the Christian faith. Infant baptism tacitly superseded infant circumcision, just as the Christian Lord's day gradually superseded the Jewish sabbath, without our having any express command for, or record of, transference. The setting aside of circumcision and of sabbaths in the case of the Gentiles was indeed expressly commanded by the apostles and Paul, but the substitution of infant baptism and of the Lord's day were tacitly adopted, not expressly enacted. No explicit mention of it occurs till Irenæus in the third century; but no society of Christians that we read of disputed its propriety till fifteen hundred years after Christ. Anabaptists would have us defer baptism till maturity as the child cannot understand the nature of it. But a child may be made heir of an estate: it is his, though incapable at the time of using or comprehending its advantage; he is not hereafter to acquire the title and claim to it: he will hereafter understand his claim, and be capable of employing his wealth: he will then, moreover, become responsible for the use he makes of it [Archbishop Whately].