Musnad Ahmad 937:153

Hajjaj and Hashim narrated to us, they said: Layth narrated to us, Yazid ibn Abi Habib narrated to me, from Ibn Shamasa: That Mu’awiyah ibn Hudayj passed by Abu Dharr while he was standing by a horse of his. He asked him: "What are you treating this horse of yours for?" He said: "I think that this horse has had its supplication answered." He said: "And what is the supplication of a beast among the beasts?" He said: "By the One in Whose hand is my soul, there is no horse but that it supplicates every dawn, saying: 'O Allah, You have placed me in the charge of a servant from among Your servants, and You have made my provision in his hand, so make me more beloved to him than his family, his wealth, and his children.'" ‘Abdullah ibn Ahmad said: My father said: "And ‘Amr ibn al-Harith agreed with him, from Ibn Shamasa."