Muwatta Malik, Book 54, Hadith 17 (USC-MSA) ⓘ

Malik related to me from Nafi from Ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, said, "No one should milk someone else's cow without his permission. Would any of you like someone to come to his apartment, break into his larder, and take his food? The udders of cows guard their food for their owners, so no one should milk someone else's cow without his permission."

وَحَدَّثَنِي مَالِكٌ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ لاَ يَحْتَلِبَنَّ أَحَدٌ مَاشِيَةَ أَحَدٍ بِغَيْرِ إِذْنِهِ أَيُحِبُّ أَحَدُكُمْ أَنْ تُؤْتَى مَشْرُبَتُهُ فَتُكْسَرَ خِزَانَتُهُ فَيُنْتَقَلَ طَعَامُهُ وَإِنَّمَا تَخْزُنُ لَهُمْ ضُرُوعُ مَوَاشِيهِمْ أَطْعِمَاتِهِمْ فَلاَ يَحْتَلِبَنَّ أَحَدٌ مَاشِيَةَ أَحَدٍ إِلاَّ بِإِذْنِهِ ‏" ‏ ‏.‏