Sahih Bukhari Volume 005, Book 058, Hadith Number 143.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 58. Merits of the Helpers in Madina (Ansaar)
Narated By Anas bin Malik : Abu Bakr and Al-'Abbas passed by one of the gatherings of the Ansar who were weeping then. He (i.e. Abu Bakr or Al-'Abbas) asked, "Why are you weeping?" They replied, "We are weeping because we remember the gathering of the Prophet with us." So Abu Bakr went to the Prophet and told him of that. The Prophet came out, tying his head with a piece of the hem of a sheet. He ascended the pulpit which he never ascended after that day. He glorified and praised Allah and then said, "I request you to take care of the Ansar as they are my near companions to whom I confided my private secrets. They have fulfilled their obligations and rights which were enjoined on them but there remains what is for them. So, accept the good of the good-doers amongst them and excuse the wrongdoers amongst them."