Hadithcore
Sahih al-Bukhari, 3890
sahih

Narrated Jabir bin `Abdullah:

I was present with my two maternal uncles at Al-`Aqaba (where the pledge of allegiance was given). (Ibn 'Uyaina said, "One of the two was Al-Bara' bin Marur.")

حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُفْيَانُ، قَالَ كَانَ عَمْرٌو يَقُولُ سَمِعْتُ جَابِرَ بْنَ عَبْدِ اللَّهِ ـ رضى الله عنهما ـ يَقُولُ شَهِدَ بِي خَالاَىَ الْعَقَبَةَ‏.‏ قَالَ أَبُو عَبْدِ اللَّهِ قَالَ ابْنُ عُيَيْنَةَ أَحَدُهُمَا الْبَرَاءُ بْنُ مَعْرُورٍ‏.‏

References2 variants
In-Book Reference
Book 63, Hadith 115
USC-MSA web (English) reference
Vol. 5, Book 58, Hadith 230 (deprecated numbering scheme)