Sahih al-Bukhari 3656
Sahih al-Bukhari · Book 62: Companions of the Prophet · "If I were to take Khalil ..."
Narrated Ibn `Abbas:
حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ ، حَدَّثَنَا وُهَيْبٌ ، حَدَّثَنَا أَيُّوبُ ، عَنْ عِكْرِمَةَ ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " وَلَوْ كُنْتُ مُتَّخِذًا مِنْ أُمَّتِي خَلِيلاً لاَتَّخَذْتُ، أَبَا بَكْرٍ وَلَكِنْ أَخِي وَصَاحِبِي " .
The Prophet (ﷺ) said, "If I were to take a Khalil, I would have taken Abu Bakr, but he is my brother and my companion (in Islam).