Sahih al-Bukhari 4843
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · The Statement of Allah the Most High: "...When they gave their Bai'a (pledge) to you (O Muḥammad pbuh) under the tree..." (V.48:18)
Narrated Thabit bin Ad-Dahhak:
حَدَّثَنِي مُحَمَّدُ بْنُ الْوَلِيدِ ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ ، حَدَّثَنَا شُعْبَةُ ، عَنْ خَالِدٍ ، عَنْ أَبِي قِلاَبَةَ ، عَنْ ثَابِتِ بْنِ الضَّحَّاكِ ـ رضى الله عنه ـ وَكَانَ مِنْ أَصْحَابِ الشَّجَرَةِ .
who was one of the companions of the tree (those who swore allegiance to the Prophet (ﷺ) beneath the tree at Al-Hudaibiya):