A wife is bound to her husband as long as he lives. But if her husband dies, she is free to be married to whom she wishes, only in the Lord.
39. The wife is bound He had previously spoken indiscriminately of husbands and wives, but as wives, on account of the modesty of their sex, might seem to have less liberty, he has thought it necessary to give in addition some special directions in reference to them. He now, therefore, teaches that women are not less at liberty than men to marry a second time, on their becoming widows.
The whole is here closed up with advice to widows: As long as the husband liveth the wife is bound by the law, confined to one husband, and bound to continue and cohabit with him. Note, The marriage - contract is for life; death only can annul the bond. But, the husband being dead, she is at liberty to marry whom she will.
Commenting on 1 Corinthians 7:39-40
The wife is bound by the law as long as her husband liveth,.... That is, she is bound to her husband, by the law of marriage, during his life; nor can the bond of marriage between them be dissolved but by the death of one of them, except in the cases of adultery, and wilful desertion, see Rom 7:2.