Albert Barnes Commentary 1 Corinthians 7:38

"So then both he that giveth his own virgin [daughter] in marriage doeth well; and he that giveth her not in marriage shall do better." — 1 Corinthians 7:38 (ASV)

Doeth well. Does right; violates no law in it, and is not to be blamed for it.

Doeth better. Does that which is on the whole to be preferred, if it can be done. He more certainly, in the present circumstances, consults her happiness by withholding her from the marriage connection than he could by allowing her to enter it.