Hadith 6019
Abu Sa'id al-Khudri reported the Prophet as saying, "The one who has been most generous to me with his companionship and property is Ab Bakr[*], and if I were to take a friend I would take Abu Bakr as a friend, but we have the brotherhood and love of Islam. No opening into the mosque must be left but that of Abu Bakr." A version has "If I were to take a friend other than my Lord, I would take Abu Bakr as a friend." *After giving Abu Bakr with the nominative, it says Bukhari read Aba Bakr. That would be more usual, as it follows inna, but see p.18. (Bukhari and Muslim.)
عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ عَنِ النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «إِنَّ مِنْ أَمَنِّ النَّاسِ عَلَيَّ فِي صُحْبَتِهِ وَمَالِهِ أَبُو بَكْرٍ - وَعِنْدَ الْبُخَارِيِّ أَبَا بَكْرٍ - وَلَوْ كُنْتُ مُتَّخِذًا خَلِيلًا لَاتَّخَذْتُ أَبَا بَكْرٍ خَلِيلًا وَلَكِنْ أُخُوَّةُ الْإِسْلَامِ وَمَوَدَّتُهُ لَا تُبْقَيَنَّ فِي الْمَسْجِدِ خَوْخَةٌ إِلَّا خَوْخَةَ أَبِي بَكْرٍ» . وَفِي رِوَايَةٍ: «لَوْ كُنْتُ مُتَّخِذًا خَلِيلًا غَيْرَ رَبِّي لَاتَّخَذْتُ أَبَا بَكْرٍ خَلِيلًا» . مُتَّفَقٌ عَلَيْهِ