Sahih Muslim 1856
صحيح مسلم#1856Sahihوَحَدَّثَنَا مُحَمَّدُ بْنُ حَاتِمٍ، حَدَّثَنَا حَجَّاجٌ، عَنِ ابْنِ جُرَيْجٍ، أَخْبَرَنِي أَبُو الزُّبَيْرِ، سَمِعَ جَابِرًا، يُسْأَلُ كَمْ كَانُوا يَوْمَ الْحُدَيْبِيَةِ قَالَ كُنَّا أَرْبَعَ عَشْرَةَ مِائَةً فَبَايَعْنَاهُ وَعُمَرُ آخِذٌ بِيَدِهِ تَحْتَ الشَّجَرَةِ وَهِيَ سَمُرَةٌ فَبَايَعْنَاهُ غَيْرَ جَدِّ ابْنِ قَيْسٍ الأَنْصَارِيِّ اخْتَبَأَ تَحْتَ بَطْنِ بَعِيرِهِ
It has been narrated on the authority of Abu Zubair who heard Jabir being questioned as to how many people were there on the Day of Hudaibiya. He replied:We were fourteen hundred. We swore fealty to him, and Umar was holding his hand while he was sitting under the tree (to administer the oath). The tree was a samura (a wild tree found in deserts). All of as took the oath of fealty at his hands except Jadd b. Qais al-Ansari who hid himself under the belly of his camel
Scholarly Authentication
The label above is the grade most of these scholars gave, each scholar counted once — 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. When they judged only its chain of narrators (“Isnaad”), the label says “Sound chain”. Each scholar's own wording:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
Sahih Muslim 1856 is the standard (Abd al-Baqi) number; this narration is #4809 in the MuslimGPT index.
In-book reference: 33:106