Only in the Lord— "Only let her take care that she marry in the Lord; and that, retaining a sense of the importance of her Christian obligation, she do not choose a partner for life of a different religion from herself." See Doddridge.
Related Commentaries of 1 Corinthians 7:39
1 Corinthians 7:39
39 The wife is bound by the law as long as her husband liveth; but if her husband be dead, she is at liberty to be married to whom she will; only in the Lord.