Musnad Abu Ya'la al-Mawsili 1:92

Zuhayr ibn Harb narrated to us, Ishaq ibn Sulayman al-Razi narrated to us, from Mughirah ibn Muslim Abu Salamah, from Farqad al-Sabakhi, from Murrah al-Tayyib, from Abu Bakr, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The bad master (sayyi' al-malakah) shall not enter Paradise." A man said: "O Messenger of Allah, did you not inform us that this nation will have the most slaves and orphans?" He said: "Honor them as you honor your own children, feed them from what you eat, and clothe them from what you wear." He said: "Then what benefit do we have of the world, O Messenger of Allah?" He said: "A horse you tether in the way of Allah, and a slave who suffices you. If he prays, then he is your brother; if he prays, then he is your brother."