For the unbelieving husband is sanctified through his believing wife, and the unbelieving wife is sanctified through her believing husband. Otherwise your children would be unclean, but now they are holy.
14. For the unbelieving husband is sanctified He obviates an objection, which might occasion anxiety to believers. The relationship of marriage is singularly close, so that the wife is the half of the man — so that they two are one flesh — (1 Corinthians 6:16) — so that the husband is the head of the wife; (Ephesians 5:23;) and she is her husband’s partner...
In this paragraph the apostle gives them direction in a case which must be very frequent in that age of the world, especially among the Jewish converts; I mean whether they were to live with heathen relatives in a married state. Moses's law permitted divorce; and there was a famous instance in the Jewish state, when the people were obliged to put away their idolatrous wives, Ezr 10:3.
Commenting on 1 Corinthians 7:10-16
For the unbelieving husband is sanctified by the wife,.... That is, "by the believing wife"; as the Vulgate Latin and Syriac versions read, and so it is read in some copies; and likewise in the next clause the same is read, by the believing husband; this is a reason given by the apostle why they should live together.