Musnad Ahmad 358:0

It was narrated from a man among the Companions of the Prophet, may Allah bless him and grant him peace, that he said: "The Messenger of Allah, may Allah bless him and grant him peace, said: 'Do not be like the people of the Book who differed after the clear proofs had come to them, so they perished. And do not be like the one who forgets Allah, so Allah makes him forget his own soul; those are the defiantly disobedient.'"