Old Testament

Matthew 5:27-28, 31-32
Lust
27You have heard that it was said, “You shall not commit adultery,”[] 28but I tell you that everyone who looks at a woman with lust has already committed adultery with her in his heart.
Divorce
31It was also said, “Whoever divorces his wife must give her a certificate of divorce.”[] 32But I tell you that whoever divorces his wife, except for sexual immorality, causes her to be regarded as an adulteress. And whoever marries the divorced woman is regarded as an adulterer.