They said to him, “Then why did Moses command us to give a certificate of divorce and to send her away?”
After Jesus’ words about the indissolubility of marriage, the Pharisees try to raise a counterargument by appealing to the Law of Moses (Deuteronomy 24:1). They ask: if God so strongly supports an unbreakable union, then why did Moses command that a man give his wife a certificate of divorce and send her away? In the next verse Jesus will explain that Moses did not command it, but permitted it under certain circumstances.