Not true.
Mar 10:3
And he answered and said unto them, What did Moses command you?
Jesus said unto them, What did Moses command you?
He did not say, What command can I formulate based upon a reality described in Genesis?
After God had made Eve from one of Adam's ribs, Moses said, Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh. From Jesus' perspective, implicit in those words was the command for a man to not put asunder what God has joined together. I will stick with Jesus' understanding of this command from Moses, and you are free to do otherwise.
Of course it's true It was the same thing as the sermon on the mount where he said, you have heard it said, but I say unto you. Likewise, you have heard Moses say to put away your wife with a bill of divorcement, but I say unto don't rip asunder what God has joined together as described in Genesis