Musannaf Ibn Abi Shayba 13:2280

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: ‘Ikrimah ibn ‘Ammar narrated to us, from ‘Alqamah ibn al-Zabraqan, he said: I said to Abu Hurayrah: "What is the right of the camels?" He said: "That you grant the one that gives much milk, give the best one, and let the stallion cover."