Allah's Messenger (ﷺ) said, "An animal should not be milked without the permission of its owner. Does any
of you like that somebody comes to his store and breaks his container and takes away his food? The
udders of the animals are the stores of their owners where their provision is kept, so nobody should
milk the animals of somebody else, without the permission of its owner."
Sahih al-Bukhari Book 45, Hadith 10