Musnad Ahmad Hadith 19404

Ali narrated to us, Mu'adh ibn Hisham narrated to us, my father narrated to me, from al-Qasim ibn 'Awf, a man from the people of Kufa, one of the Banu Murrah ibn Hammam, from 'Abd al-Rahman ibn Abi Layla, from his father, from Mu'adh ibn Jabal, who said: He came to al-Sham and saw the Christians, and he mentioned its meaning, except that he said: So I said, "Why do you do this?" They said, "This was the greeting of the prophets before us." So I said, "We are more deserving to do this with our Prophet." So the Prophet of Allah, peace and blessings be upon him, said: "They have lied about their prophets just as they have altered their book. Indeed, Allah, Mighty and Majestic, has given us something better than that: the greeting of peace, the greeting of the people of Paradise."