Sahih (Sahih al-Bukhari)
حَدَّثَنَا أَبُو نُعَيْمٍ، حَدَّثَنَا مِسْعَرٌ، عَنْ عَبْدِ الْمَلِكِ بْنِ مَيْسَرَةَ، عَنِ النَّزَّالِ، قَالَ أَتَى عَلِيٌّ ـ رضى الله عنه ـ عَلَى باب الرَّحَبَةِ، فَشَرِبَ قَائِمًا فَقَالَ إِنَّ نَاسًا يَكْرَهُ أَحَدُهُمْ أَنْ يَشْرَبَ وَهْوَ قَائِمٌ، وَإِنِّي رَأَيْتُ النَّبِيَّ صلى الله عليه وسلم فَعَلَ كَمَا رَأَيْتُمُونِي فَعَلْتُ.
Narrated An-Nazzal:Ali came to the gate of the courtyard (of the Mosque) and drank (water) while he was standing and said, "Some people dislike to drink while standing, but I saw the Prophet (ﷺ) doing (drinking water) as you have seen me doing now