Imam Ali's (AS) last will to his sons Imam Hasan (AS) and Imam Hussain (AS) after the attempt on his life by a stab from Ibn Muljam:
My advice to you is to be conscious of Allah and steadfast in your religion. Do not yearn for the world, and do not be seduced by it. Do not resent anything you have missed in it. Proclaim the truth; work for the next world. Oppose the oppressor and support the oppressed.
I advise you, and all my children, my relatives, and whosoever receives this message, to be conscious of Allah, to remove your differences, and to strengthen your ties. I heard your grandfather, peace be upon him, say: "Reconciliation of your differences is more worthy than all prayers and all fasting." Fear Allah in matters concerning orphans. Attend to their nutrition and do not forget their interests in the middle of yours.
Fear Allah in your relations with your neighbors. Your Prophet often recommended them to you, so much so that we thought he would give them a share in inheritance.
Remain attached to the Quran. Nobody should surpass you in being intent on it, or more sincere in implementing it.
Fear Allah in relation to your prayers. It is the pillar of your religion.
Fear Allah in relation to His House; do not abandon it as long as you live. It you should do that you would abandon your dignity.
Persist in jihad in the cause of Allah, with your money, your souls, and your tongue.
Maintain communication and exchange of opinion among yourselves. Beware of disunity and enmity. Do not desist from promoting good deeds and cautioning against bad ones. Should you do that,the worst among you would be your leaders, and you will call upon Allah without response.
O Children of Abdul Mattaleb! Do not shed the blood of Muslims under the banner: The Imam has been assassinated! Only the assassin should be condemned to death.
If I die of this stab of his, kill him with one similar stroke. Do not mutilate him! I have heard the Prophet, peace be upon him, say: "Mutilate not even a rabid dog."