Matthew 19:3-9

3 The Pharisees also came to Him, testing Him, and saying to Him, "Is it lawful for a man to divorce his wife for just any reason?"

4 And He answered and said to them, "Have you not read that He who made them at the beginning 'made them male and female,'

5 and said, 'For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh'?

6 So then, they are no longer two but one flesh. Therefore what God has joined together, let not man separate."

7 They said to Him, "Why then did Moses command to give a certificate of divorce, and to put her away?"

8 He said to them, "Moses, because of the hardness of your hearts, permitted you to divorce your wives, but from the beginning it was not so.

9 And I say to you, whoever divorces his wife, except for sexual immorality, and marries another, commits adultery; and whoever marries her who is divorced commits adultery."