39 And so like a good physician, desiring to preserve the stability of virtue in the strong, and to give health to the weak, he gives counsel to the one, and points out the remedy to the others: “He that is weak eats herbs,” let him take a wife; he that has more power let him seek the stronger meat of virtue. And rightly he added: “For he who being steadfast has settled in his own heart, having no necessity, but has power over his own will, and has determined this in his own heart, to keep his own virgin, does well. So then both he who gives his own virgin in marriage, does well; and he that gives her not in marriage, does better. A woman is bound by the law, for so long a time as her husband lives. But if her husband have fallen asleep, she is freed, let her marry whom she will, only in the Lord. But she will be more happy if she abide as she is, after my counsel, for I think that I also have the Spirit of the Lord.” This is to have the counsel of God, to search diligently into all things, and to advise things that are best, and to point out those that are safest.
Source: Letters (New Advent)