Romans 7:3

This accounts for the fact that if during her husband's life she lives with another man, she will be stigmatized as an adulteress; but that if her husband is dead she is no longer under the old prohibition, and even though she marries again, she is not an adulteress.

Matthew 5:32

But I tell you that every man who puts away his wife except on the ground of unfaithfulness causes her to commit adultery, and whoever marries her when so divorced commits adultery.

Mark 10:6-12

but from the beginning of the creation the rule was, 'Male and female did God make them.

John 8:3-5

and was teaching them when the Scribes and the Pharisees brought to Him a woman who had been found committing adultery. They made her stand in the centre of the court, and they put the case to Him.

1 Timothy 5:11-14

But the younger widows you must not enrol; for as soon as they begin to chafe against the yoke of Christ, they want to marry,

Treasury of Scripture Knowledge

Summary

So then if, while her husband liveth, she be married to another man, she shall be called an adulteress: but if her husband be dead, she is free from that law; so that she is no adulteress, though she be married to another man.

General references

Bible References

So then

Matthew 5:32
But I tell you that every man who puts away his wife except on the ground of unfaithfulness causes her to commit adultery, and whoever marries her when so divorced commits adultery.
Mark 10:6
but from the beginning of the creation the rule was, 'Male and female did God make them.
John 8:3
and was teaching them when the Scribes and the Pharisees brought to Him a woman who had been found committing adultery. They made her stand in the centre of the court, and they put the case to Him.

Though

1 Timothy 5:11
But the younger widows you must not enrol; for as soon as they begin to chafe against the yoke of Christ, they want to marry,

General references

Mark 10:9
What, therefore, God has joined together let not man separate."