From the will of Imam Ali (peace be upon him), which he addressed to his two sons, Hasan and Hussain (peace be upon them), his family, and the future generations of the Islamic nation:

“Be an opponent to the oppressor and a supporter of the oppressed. I advise you, and all my family, my relative, and whoever receives my letter, to fear Allah, to organize your affairs, and to maintain good relations among yourselves… By Allah, be mindful of the orphans… By Allah, be mindful of your neighbors… By Allah, be mindful of the Quran… By Allah, be mindful of the House of your Lord—do not abandon it as long as you live… By Allah, be mindful of striving in His cause with your wealth, your lives, and your tongues. Maintain ties with one another, be generous to one another, and beware of turning against or cutting off one another. Do not abandon enjoining good and forbidding evil, then the worst among you take power over you, and then you pray, but your prayers will not be answered.”