Some Pharisees came to him to test him. They asked, “Is it lawful for a man to divorce his wife for any and every reason?” Jesus replied, “Moses permitted you to divorce your wives because your hearts were hard.”

Matthew 19:3, 8

It seems strange to me that the Pharisees should have asked about divorce as Jesus was moving toward Jerusalem, and the Cross.  I suppose the key to understanding their question is found in the phrase, “Some Pharisees came to him to test him.”  They are still hoping to discredit Jesus by getting him to debate with them about matters of the Law, now regarding marriage and divorce.  The Pharisees had strict laws about such things while the Sadducees were more tolerant.

Jesus based his answer on Moses as well.  He said that Moses allowed for divorce in some cases, “because your hearts were hard.”  Not “their hearts” but “your hearts.”  Jesus reminded them that Moses made allowance for human weakness.  Their position on the Law did not permit this interpretation.  They would not agree for a moment that their hearts were hard.  They did not pay much attention to what is on the heart, but on the Law of Moses!

Of course, the Pharisees would not agree that their hearts were hard.  They prided themselves in obeying that Law precisely as their way of pleasing God.  They were obedient to the letter.

Once again, Jesus pointed to the grace of God that made a way for sinners, in contrast to the Pharisees who saw themselves as righteous, certainly not sinners in need of grace.