They say to him, “Why then did Moses command to give her a certificate of divorce and send her away?”a Bible see other translations
Alluding to Deut. 24:1-4

“command.” The hard-hearted Pharisees used the word “command,” emphasizing their belief that if a woman committed adultery the husband had to divorce her. Jesus gently corrected their belief by saying Moses “allowed” (or “permitted”) divorce (Matt. 19:8), but it certainly was not a command. Many marriages have been healed even though one spouse committed adultery.

Commentary for: Matthew 19:7