Romans 7:1-3

Brothers and sisters (I'm speaking here to people who know the law), don't you see that the law has authority over someone only while they're alive? For example, a married woman is bound by the law to her husband while he's alive, but if he dies, she's released from this legal obligation to him. So if she lives with another man while her husband is alive, she would be committing adultery. However, if her husband dies and then she marries another man, she wouldn't be guilty of adultery.