As the Pharisees try to trap Jesus on the issue of marriage by making him side with one of the rabbinical schools of thought of the day, He confounds all in His hearing with the fulfillment of the law: "What therefore God has joined together, let no man separate." Even though these religious leaders could only recall the case law that was given because of the hardness of their hearts, Jesus points them to Moses' words in the beginning of Genesis to show them the one flesh union between man and woman as long as they both shall live.