The Messenger of Allah (s) delivered a sermon to the people in his Farewell Pilgrimage in Mina in the Mosque of Khayf. So, he praised Allah and commended Him. Then, he said: May Allah grant joy to a servant who heard my sayings and understood them, then delivers them to those who did not hear them. There can be a carrier of knowledge who is not a person of understanding, and there could be a carrier of knowledge who brings it to one who is more knowledgeable than him. There are three things that the heart of a Muslim person does not feel trouble in: (1) sincerity in deeds for Allah, (2) wishing well for the Imams of the Muslims, and (3) sticking to their community (jama`a), for their supplications encompass those behind them. The Muslims are brethren: their blood is equivalent, and [even] the lowest of them strives to protect them. They are [one] hand against those who oppose them.