Sahih Muslim 2009 a
Abu Bakr Siddiq reported:
As we went along with Allah's Messenger (ﷺ) from Mecca to Medina, we passed by a shepherd and Allah's Messenger (ﷺ) was feeling thirsty. He (Abu Bakr Siddiq) said: I milked for him a small quantity of milk (from his goat) and brought it to him (the Holy Prophet), and he drank it and I was very happy.
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ الْعَنْبَرِيُّ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، عَنْ أَبِي إِسْحَاقَ،
 عَنِ الْبَرَاءِ، قَالَ قَالَ أَبُو بَكْرٍ الصِّدِّيقُ لَمَّا خَرَجْنَا مَعَ النَّبِيِّ صلى الله عليه وسلم مِنْ مَكَّةَ
 إِلَى الْمَدِينَةِ مَرَرْنَا بِرَاعٍ وَقَدْ عَطِشَ رَسُولُ اللَّهِ صلى الله عليه وسلم قَالَ فَحَلَبْتُ لَهُ كُثْبَةً
 مِنْ لَبَنٍ فَأَتَيْتُهُ بِهَا فَشَرِبَ حَتَّى رَضِيتُ ‏.‏