The Messenger of Allah ﷺ said, "When an animal is given as collateral, the one holding it as security is responsible for its feed. The milk of a milking animal may be drunk, and the one who drinks it must bear its upkeep. Likewise, it may be ridden, and the one who rides it must bear its upkeep."
حدثنا هشيم عن زكريا عن الشعبي
قال رسول الله ﷺ إذا كانت الدابة مرهونة فعلى المرتهن علفها ولبن الدر يشرب وعلى الذي يشربه نفقته ويركب
Its isnad is sahih. Zakariya is Ibn Abu Zaida, whose reliability was already established at 2055, and we add here that Ibn Abu Hatim gave his biography in al-Jarh wal-Tadil, 1/593/2–594.Bukhari related the hadith in similar wording, 5:101–102, through the narration of Abu Naeem and through the narration of Abdullah bin Mubarak, both of them from Zakariya, with this isnad. The group [of hadith compilers] except Muslim and Nasai also related it in similar wording, as found in al-Muntaqa, 2976.As for this particular narration, the narration of Hushaym from Zakariya, the author of al-Muntaqa, 2977, attributed it to Ahmad alone. The Hafiz pointed out in Fath al-Bari, 5:102, that Tahawi related it through the route of Ismail bin Salim al-Saigh from Hushaym, and that Ibn Hazm criticized it as being among Ismail's confused narrations. But he responded to this by noting that Ahmad related it in the same way, this being the very narration at hand, and that Daraqutni also related it, through the route of Ziyad bin Ayub from Hushaym.Al-durr, the Hafiz said, with the consonant vowelled fatha and the r doubled, is a verbal noun meaning "possessing milk," that is, having an udder full of milk. His statement "the milk of al-durr" is an instance of attaching a thing to itself.