Sahih al-Bukhari 1637
صحيح البخاري#1637Sahihحَدَّثَنَا مُحَمَّدٌ ـ هُوَ ابْنُ سَلاَمٍ ـ أَخْبَرَنَا الْفَزَارِيُّ، عَنْ عَاصِمٍ، عَنِ الشَّعْبِيِّ، أَنَّ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ حَدَّثَهُ قَالَ سَقَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم مِنْ زَمْزَمَ فَشَرِبَ وَهُوَ قَائِمٌ. قَالَ عَاصِمٌ فَحَلَفَ عِكْرِمَةُ مَا كَانَ يَوْمَئِذٍ إِلاَّ عَلَى بَعِيرٍ.
Narrated Ibn `Abbas:I gave Zamzam water to Allah's Messenger (ﷺ) and he drank it while standing. `Asim (a sub-narrator) said that `Ikrima took the oath that on that day the Prophet (ﷺ) had not been standing but riding a camel
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 25:120