Matthew 5:31

"It was also said, 'Whoever divorces his wife must give her a certificate of divorce.'

Then they asked Him, "Why did Moses command us to give a written divorce charge, and in this way to divorce a wife?"

And some Pharisees came up to Him, to try Him out with the question, "Is it right for a man to divorce his wife for any cause?"

Some Pharisees came up, and to test Him they began to ask Him whether a man should be allowed to divorce his wife.

Treasury of Scripture Knowledge

It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement:

They answered, "Moses allowed a man to divorce his wife, if he wrote out a divorce charge."