That the Prophet ﷺ said: "When one of you comes upon livestock, if its owner is with it then seek his permission. If he permits him then let him milk it and drink. If there is no one with it then call out three times, if someone answers then seek his permission. If no one answers then let him milk it and drink without carrying (any of it away)." [He said:] There are narrations on this topic from Ibn 'Umar and Abu Sa'eed.  

أَنَّ النَّبِيَّ ﷺ قَالَ إِذَا أَتَى أَحَدُكُمْ عَلَى مَاشِيَةٍ فَإِنْ كَانَ فِيهَا صَاحِبُهَا فَلْيَسْتَأْذِنْهُ فَإِنْ أَذِنَ لَهُ فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَلاَ يَحْمِلْ وَإِنْ لَمْ يَكُنْ فِيهَا أَحَدٌ فَلْيُصَوِّتْ ثَلاَثًا فَإِنْ أَجَابَهُ أَحَدٌ فَلْيَسْتَأْذِنْهُ فَإِنْ لَمْ يُجِبْهُ أَحَدٌ فَلْيَحْتَلِبْ وَلْيَشْرَبْ وَلاَ يَحْمِلْ قَالَ وَفِي الْبَابِ عَنْ عُمَرَ وَأَبِي سَعِيدٍ