ibn Umar · The Book of al-Bay'ah

"I came to the Prophet when he was accepting (the people's) pledge, and said: 'O Messenger of Allah, extend you hand so that I may give you my pledge, and state your terms, for you know best.' He said: 'I accept you pledge that you will worship Allah, establish Salah, pay the Zakah, be sincere toward the Muslims, and forsake the idolaters."

"I heard 'Ubadah bin As-Samit say: 'I pledged to the Messenger of Allah among a group of people, and he said: I accept your pledge that you will not associate anything with Allah, you will not steal, you will not have unlawful sexual relations, you will not kill you children, you will not utter slander, fabricating from between your hands and feet, and you will not disobey me when commanded with goodness. Whoever fulfills (this pledge), his reward will be…

"The Imam is like a shield whose orders should be obeyed when they (the Muslims) fight, and where they should seek protection. If he enjoins fear of Allah and behaves justly, then he will be rewarded, but if he enjoins otherwise, then it will be a burden (of sin) on him."