From Sahih Bukhari (Hadith 3800):
Narrated Ibn `Abbas:Allah's Messenger (ﷺ) (in his fatal illness) came out wrapped in a sheet covering his shoulders and his head was tied with an oily tape of cloth till he sat on the pulpit, and after praising and glorifying Allah, he said, "Then-after, O people! The people will go on increasing, but the Ansar will go on decreasing till they become just like salt in a meal. So whoever amongst you will be the ruler and has the power to harm or benefit others, should accept the good of the good-doers amongst them and excuse the wrongdoers amongst them
Reference: Bukhari 3800