Apparently, when Jesus mentions divorce in Matthew 19, he is stating his position on the Shammai/Hillel debate. He is not talking about the legitimacy of divorce in general. No rabbi would have asked, "Is it lawful for someone to divorce?"; it would have been like asking, "Is it lawful to do what Moses said in the law?"

Jesus sided with Shammai on the interpretation of Deuteronomy 24:1. But Jesus and Paul (and Shammai) would have shared the rabbinic understanding that divorce is regrettable but permissible when the vow of fidelity, provision, or love has been broken and there is no repentance. This would include abuse and abandonment.

That is how I was taught to interpret it by my OT professor.