Musnad Ahmad 1034:99

Husayn ibn Muhammad narrated to us, Sufyan—meaning Ibn ‘Uyaynah—narrated to us, from ‘Abd al-Malik, from Rib’i, from Hudhayfah, who said: A man came to the Prophet, peace and blessings of Allah be upon him, and said: "I saw in a dream that I met some of the People of the Book, and he said: 'You are a good people, were it not that you say: "What Allah wills and what Muhammad wills."'" The Prophet, peace and blessings of Allah be upon him, said: "I used to dislike that from you, so say: 'What Allah wills, then what Muhammad wills.'"