Sahih Bukhari
Merits of the Helpers in Madinah (Ansaar)
Volume: 005 / Book Number: 058 / Hadith Number: 145
Narrated Anas bin Malik:
The Prophet said, "The Ansar are my near companions to whom I confided my private secrets, People will go on increasing but the Ansar will go on decreasing; so accept the good of the good-doers amongst them and excuse the wrong-doers amongst them. "