Marriage: Infidelity of Those Contracted In, Punished As If Married
Source: TTT
Deuteronomy 22:23, 24
If there is a virgin pledged in marriage to a man, and another man encounters her in the city and sleeps with her, / you must take both of them out to the gate of that city and stone them to death—the young woman because she did not cry out in the city, and the man because he has violated his neighbor’s wife. So you must purge the evil from among you.
Matthew 1:19
Because Joseph her husband was a righteous man and was unwilling to disgrace her publicly, he resolved to divorce her quietly.