The Book on Government
33/18. Chapter:
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
Sahih Muslim
حَدَّثَنَا سَعِيدُ بْنُ عَمْرٍو الأَشْعَثِيُّ، وَسُوَيْدُ بْنُ سَعِيدٍ، وَإِسْحَاقُ بْنُ إِبْرَاهِيمَ، وَأَحْمَدُ، بْنُ عَبْدَةَ - وَاللَّفْظُ لِسَعِيدٍ قَالَ سَعِيدٌ وَإِسْحَاقُ أَخْبَرَنَا وَقَالَ الآخَرَانِ، حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرٍو، عَنْ جَابِرٍ، قَالَ كُنَّا يَوْمَ الْحُدَيْبِيَةِ أَلْفًا وَأَرْبَعَمِائَةٍ فَقَالَ لَنَا النَّبِيُّ صلى الله عليه وسلم " أَنْتُمُ الْيَوْمَ خَيْرُ أَهْلِ الأَرْضِ " . وَقَالَ جَابِرٌ لَوْ كُنْتُ أُبْصِرُ لأَرَيْتُكُمْ مَوْضِعَ الشَّجَرَةِ.
It has been narrated (through a different chain of transmitters) on the authority of Jabir who said: We were one thousand and four hundred on the Day of Hudaibiya when the Prophet (ﷺ) said to us: Today you are the best people on the earth. And Jabir said: If I had the eyesight, I could show you the place of the tree.
Reference : Sahih Muslim 1856eIn-book reference : Book 33, Hadith 108USC-MSA web (English) reference : Book 20, Hadith 4580