Musannaf Ibn Abi Shayba 33:163

Affan narrated to us, he said: Hammad bin Salamah narrated to us, from al-Jurayri, from Abu Nadrah, from Abdullah bin Mawlah, from Buraydah al-Aslami, from the Prophet, peace and blessings of Allah be upon him, who said: "It is sufficient for one of you from the world to have a servant and a mount."