Romans 7:2-3; 1 Corinthians 7:39

Romans 7:2-3

2 For a married woman is bound by law to her husband while he lives, but if her husband dies she is released from the law of marriage.

3 Accordingly, she will be called an adulteress if she lives with another man while her husband is alive. But if her husband dies, she is free from that law, and if she marries another man she is not an adulteress.

1 Corinthians 7:39

39 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.