Musnad Ahmad 1164:4

Abu Nu‘aym narrated to us, he said: Sufyan narrated to us, from Salamah, from Abu Idris al-Murhabi, from Muslim ibn Safwan, from Safiyyah, she said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "People will not cease..." and he mentioned the hadith and narrated it in full.