31 "It was also said, 'Whoever divorces his wife, let him give her a certificate of divorce.'
32 But I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery.
3 And Pharisees came up to him and tested him by asking, "Is it lawful to divorce one's wife for any cause?"
4 He answered, "Have you not read that he who created them from the beginning made them male and female,
5 and said, 'Therefore a man shall leave his father and his mother and hold fast to his wife, and the two shall become one flesh'?
6 So they are no longer two but one flesh. What therefore God has joined together, let not man separate."
7 They said to him, "Why then did Moses command one to give a certificate of divorce and to send her away?"
8 He said to them, "Because of your hardness of heart Moses allowed you to divorce your wives, but from the beginning it was not so.
9 And I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery."
The Lord never said divorce is allowed only on the grounds of infidelity. In context He is speaking solely to the men, and their hardheartedness regarding their wives.
What is being said is simply this; when you divorce your wife for any and all arbitrary reasons and she ends up marrying another,the husband who divorced her is causing her to commit adultery. Also, a man who marries a divorced woman commits adultery.
However if a man divorces his wife because she has already committed adultery, he is not responsible for causing her to commit adultery since she already has committed.that sin.
Chris came to fulfill all the law and the prophets and so He has. The time for legalism aka hardheartedness is through, fulfilled in Christ.
There are no "biblical grounds" for divorce.
10 To the married I give this charge (not I, but the Lord): the wife should not separate from her husband 11 (but if she does, she should remain unmarried or else be reconciled to her husband), and the husband should not divorce his wife.Deuteronomy 24:1-4; 1 Corinthians 7:10-17