1 Corinthians 7:2, 28, 36, 39

Nevertheless, to avoid fornication, let every man have his own wife, and let every woman have her own husband.

But and if thou marry, thou hast not sinned; and if a virgin marry, she hath not sinned. Nevertheless such shall have trouble in the flesh: but I spare you.

But if any man think that he behaveth himself uncomely toward his virgin, if she pass the flower of her age, and need so require, let him do what he will, he sinneth not: let them marry.

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.