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) Sahih al-Bukhari 4843
Arabic hadith text
حَدَّثَنِي مُحَمَّدُ بْنُ الْوَلِيدِ، حَدَّثَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، حَدَّثَنَا شُعْبَةُ، عَنْ خَالِدٍ، عَنْ أَبِي قِلاَبَةَ، عَنْ ثَابِتِ بْنِ الضَّحَّاكِ ـ رضى الله عنه ـوَكَانَ مِنْ أَصْحَابِ الشَّجَرَةِ
Translation
Narrated Thabit bin Ad-Dahhak
who was one of the companions of the tree (those who swore allegiance to the Prophet (ﷺ) beneath the tree at Al-Hudaibiya):