Scripture on Bible.com: Mark 10:1-9
1 And he left there and went to the region of Judea and beyond the Jordan, and crowds gathered to him again. And again, as was his custom, he taught them. 2 And Pharisees came up and in order to test him asked, “Is it lawful for a man to divorce his wife?” 3 He answered them, “What did Moses command you?” 4 They said, “Moses allowed a man to write a certificate of divorce and to send her away.” 5 And Jesus said to them, “Because of your hardness of heart he wrote you this commandment. 6 But from the beginning of creation, ‘God made them male and female.’ 7 ‘Therefore a man shall leave his father and mother and hold fast to his wife, 8 and the two shall become one flesh.’ So they are no longer two but one flesh. 9 What therefore God has joined together, let not man separate.”