Musnad Abu Ya'la al-Mawsili 166:1

'Abdullah ibn Muhammad ibn Asma' narrated to us, Mahdi ibn Maymun narrated to us, Muhammad ibn 'Abdullah ibn Abi Ya'qub narrated to us, from al-Hasan ibn Sa'd, the freed slave of al-Hasan ibn 'Ali, from 'Abdullah ibn Ja'far, who said: The Messenger of Allah (ﷺ) seated me behind him one day. He whispered a secret to me that I would not tell to anyone among the people. The most beloved thing for the Messenger of Allah (ﷺ) to use as a screen for his need was a mound or a garden of date palms—meaning a wall. He entered the garden of a man from the Ansar, and behold, there was a camel in it. When it saw the Prophet (ﷺ), it became agitated and its eyes shed tears. The Prophet (ﷺ) went to it and wiped its head, up to its hump and its ears, so it calmed down. He then said, "Who is the master of this camel? To whom does this camel belong?" A young man from the Ansar came and said, "It is mine, O Messenger of Allah." He said, "Do you not fear Allah regarding this beast which Allah has placed in your possession? For it has complained to me that you starve it and tire it out."