‘Abd Allah bin Umar reported the Apostle of Allaah ﷺ as saying “One should not milk the cattle of anyone without his permission. Does anyone of you like that any one approaches his corn cell and its storage is broken and then the corn scatters away? Likewise, the teats of their Cattle store their food. Therefore none of you should milk the cattle of anyone without his permission.”  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لاَ يَحْلُبَنَّ أَحَدٌ مَاشِيَةَ أَحَدٍ بِغَيْرِ إِذْنِهِ أَيُحِبُّ أَحَدُكُمْ أَنْ تُؤْتَى مَشْرَبَتُهُ فَتُكْسَرَ خِزَانَتُهُ فَيُنْتَثَلَ طَعَامُهُ فَإِنَّمَا تَخْزُنُ لَهُمْ ضُرُوعُ مَوَاشِيهِمْ أَطْعِمَتَهُمْ فَلاَ يَحْلُبَنَّ أَحَدٌ مَاشِيَةَ أَحَدٍ إِلاَّ بِإِذْنِهِ