ʿAlī saw the Prophet ﷺ drink standing up

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."  

أَتَى عَلِيٌّ ؓ عَلَى باب الرَّحَبَةِ فَشَرِبَ قَائِمًا فَقَالَ: إِنَّ نَاسًا يَكْرَهُ أَحَدُهُمْ أَنْ يَشْرَبَ وَهْوَ قَائِمٌ، وَإِنِّي رَأَيْتُ النَّبِيَّ ﷺ فَعَلَ كَمَا رَأَيْتُمُونِي فَعَلْتُ۔  

"We would eat during the time of the Messenger of Allah ﷺ while we were walking, and we would drink while we were standing."  

كُنَّا نَأْكُلُ عَلَى عَهْدِ رَسُولِ اللَّهِ ﷺ وَنَحْنُ نَمْشِي وَنَشْرَبُ وَنَحْنُ قِيَامٌ  

From his father, from his grandfather who said: "I saw the Messenger of Allah ﷺ drinking while standing and sitting."  

رَأَيْتُ رَسُولَ اللَّهِ ﷺ يَشْرَبُ قَائِمًا وَقَاعِدًا  

that Allah's Apostle ( ﷺ) forbade that a person should drink while standing. Qatada reported: We said to him: What about eating? Thereupon he (Anas) said: That is even worse and more detestable (abominable).  

عَنِ النَّبِيِّ ﷺ أَنَّهُ نَهَى أَنْ يَشْرَبَ الرَّجُلُ قَائِمًا قَالَ قَتَادَةُ فَقُلْنَا فَالأَكْلُ فَقَالَ ذَاكَ أَشَرُّ أَوْ أَخْبَثُ  

None of you should drink while standing; and if anyone forgets, he must vomit.  

قَالَ رَسُولُ اللَّهِ ﷺ لاَ يَشْرَبَنَّ أَحَدٌ مِنْكُمْ قَائِمًا فَمَنْ نَسِيَ فَلْيَسْتَقِئْ