Sahih al-Bukhari 58
Narrated Ziyad bin'Ilaqa:
I heard Jarir bin 'Abdullah (Praising Allah). On the day when 
     Al-Mughira bin Shu'ba died, he (Jarir) got up (on the pulpit) and 
     thanked and praised Allah and said, "Be afraid of Allah alone Who has 
     none along with Him to be worshipped.(You should) be calm and quiet 
     till the (new) chief comes to you and he will come to you soon. Ask 
     Allah's forgiveness for your (late) chief because he himself loved to 
     forgive others." Jarir added, "Amma badu (now then), I went to the 
     Prophet and said, 'I give my pledge of allegiance to you for Islam." 
     The Prophet (ﷺ) conditioned (my pledge) for me to be sincere and true to 
     every Muslim so I gave my pledge to him for this. By the Lord of this 
     mosque! I am sincere and true to you (Muslims). Then Jarir asked for 
     Allah's forgiveness and came down (from the pulpit).
حَدَّثَنَا أَبُو النُّعْمَانِ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ زِيَادِ بْنِ عِلاَقَةَ، قَالَ سَمِعْتُ جَرِيرَ بْنَ عَبْدِ اللَّهِ، يَقُولُ يَوْمَ مَاتَ الْمُغِيرَةُ بْنُ شُعْبَةَ قَامَ فَحَمِدَ اللَّهَ وَأَثْنَى عَلَيْهِ وَقَالَ عَلَيْكُمْ بِاتِّقَاءِ اللَّهِ وَحْدَهُ لاَ شَرِيكَ لَهُ، وَالْوَقَارِ وَالسَّكِينَةِ حَتَّى يَأْتِيَكُمْ أَمِيرٌ، فَإِنَّمَا يَأْتِيكُمُ الآنَ، ثُمَّ قَالَ اسْتَعْفُوا لأَمِيرِكُمْ، فَإِنَّهُ كَانَ يُحِبُّ الْعَفْوَ‏.‏ ثُمَّ قَالَ أَمَّا بَعْدُ، فَإِنِّي أَتَيْتُ النَّبِيَّ صلى الله عليه وسلم قُلْتُ أُبَايِعُكَ عَلَى الإِسْلاَمِ‏.‏ فَشَرَطَ عَلَىَّ وَالنُّصْحِ لِكُلِّ مُسْلِمٍ‏.‏ فَبَايَعْتُهُ عَلَى هَذَا، وَرَبِّ هَذَا الْمَسْجِدِ إِنِّي لَنَاصِحٌ لَكُمْ‏.‏ ثُمَّ اسْتَغْفَرَ وَنَزَلَ‏.‏