Hadith 112

Sahih Muslim

Book 33: The Book on Government

Chapter 18

It is recommended for the army to swear allegiance to the ruler when intending to fight, and an account of Bay'at Ar-Ridwan beneath the tree

باب اسْتِحْبَابِ مُبَايَعَةِ الإِمَامِ الْجَيْشَ عِنْدَ إِرَادَةِ الْقِتَالِ وَبَيَانِ بَيْعَةِ الرِّضْوَانِ تَحْتَ الشَّجَرَةِ

Sahih Muslim 1857a
حَدَّثَنَا عُبَيْدُ اللَّهِ بْنُ مُعَاذٍ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، عَنْ عَمْرٍو، - يَعْنِي ابْنَ مُرَّةَ - حَدَّثَنِي عَبْدُ اللَّهِ بْنُ أَبِي أَوْفَى، قَالَ كَانَ أَصْحَابُ الشَّجَرَةِ أَلْفًا وَثَلاَثَمِائَةٍ وَكَانَتْ أَسْلَمُ ثُمُنَ الْمُهَاجِرِينَ ‏.‏
It has been narrated on the authority of 'Abdullah b. Abu Aufa

The Companions of the Tree (i e. those who swore fealty under the tree) were one thousand and three hundred, and the people of Aslam tribe were one-eighth of the Muhajirs.