For Imam al-Hasan and Imam al-Husayn (peace be upon them) when Abd ur Rahman Ibne Muljam (the curse of Allah be upon him) struck him (fatally with a sword).
I advise you to fear Allah and that you should not hanker after the (pleasures of this) world even though it may run after you. Do not be sorry for anything of this world that you have been denied. Speak the truth and act (in expectation) for reward. Be an enemy of the oppressor and helper of the oppressed.
I advise you (both) and all my children and members of my family and everyone whom my writing reaches, to fear Allah, to keep your affairs in order, and to maintain good relations among yourselves for I have heard your grandfather (the Holy Prophet – pbuh) saying, "Improvement of mutual differences is better than general prayers and fasting."
(Fear) Allah (and) keep Allah in view in the matter of orphans. So do not allow them to starve and they should not be ruined in your presence. (Fear)Allah (and) keep Allah in view in the matter of your neighbours, because they were the subject of the Prophet's advice. He went on advising in their favour till we thought he would allow them a share in inheritance.
(Fear) Allah, keep Allah in view in the matter of the Quran. No one should excel you in acting upon it. (Fear) Allah, keep Allah in view in the matter of prayer, because it is the pillar of your religion. (Fear) Allah, keep Allah in view in the matter of your Lord's House (Ka’aba). Do not forsake it so long as you live, because if it is abandoned you will not be spared. (Fear) Allah (and) keep Allah in view in the matter of jihad with the help of your property, lives and tongues in the way of Allah.
You should keep to a respect for kinship and spending for others. Avoid turning away from one another and severing mutual relations. Do not give up bidding for good and forbidding from evil lest the mischievous gain positions over you, and then if you will pray, the prayers will not be granted.
Then he said: O sons of Abdul Muttalib, you should not shed blood of Muslims shouting Ameerul Momineen has been killed." Beware, do not kill on account of me except my killer. Wait till I die by his existing stroke. Then strike him one stroke for his stroke and do not dismember the limbs of the man, for I have heard the Messenger of Allah (pbuh) saying, "Avoid cutting limbs even though it may be a rabid dog."