Matthew Poole and continuators on 1 Corinthians 7:14

14 For the unbelieving husband is sanctified by the wife, and the unbelieving wife is sanctified by the husband; Else were your children unclean , but now they are holy .

Sanctifying in holy Writing generally signifieth the separation, or setting apart of a person or thing from a common, to, and for an holy use, whether it be by some external Rites and Ceremonies, or by the infusing of some inward spiritual habits. In this place it seemeth to have a different sense from what it usually hath in holy Writ; for it can neither signifie the sanctification of the person by in[illegible: 1 letter]used habits of Grace; for neither is the unbelieving husband thus sanctified by the believing wi[illegible: 1 letter]e, neither is the unbelieving wife thus sanctified by the believing husband. Nor are either of them thus set apart for the service of God by any legal Rites, which hath made a great difference in the notions of Interpreters, how the unbelieving husband is sanctified by the believing wife, or the unbelieving wife by the believing husband. Some think it signifies no more than prepared for God, as sanctified signifies, Isa. 13.3. Others think they are sanctified by a moral denomination, I rather think it signifies brought into such a state, that the Believer, without offence to the Law of God, may continue in a married estate with such a yoke-fellow: and the state of marriage is an holy state, notwithstanding the disparity with reference to Religion.

Otherwise he saith, the children begotten and born of such parents would be unclean, in the same state that the children of Pagan parents are without the Church, not within the Covenant, not under the Promise. In one sense all children are unclean, i. e. children of wrath, born in sin, and brought forth in iniquity; but all are not in this sense unclean, some are within the Covenant of Grace, within the Church, capable of Baptism.

These are those that are called holy, not as inwardly renewed and sanctified, but relatively, in the same sense that all the Jewish Nation are called an holy people; and possibly this may give us a further light to understand the term sanctified, in the former part of the verse. The unbelieving husband is so far sanctified by the believing wife, and the unbelieving wife so far sanctified by the believing husband, that as they may lawfully continue in their married relation, and live together as man and wife, so the issue coming from them both shall he by God counted in Covenant with him, and have a right to Baptism, which is one of the Seals of that Covenant, as well as those children both whose parents are Believers.