In the name of God, the most merciful, the most mercy-giving; this is Ali ibn Abitaleb’s will. Ali witnesses in the unity and uniqueness of God and confesses that Mohammad (PBUH) is the servant and the Prophet of God, God has sent him to guide people in order to make God’s religion dominant on other religions despite the dislike of the disbelievers.
Verily, my Salaat, prayers, life and death are from God and for God, there is no partner to God, I have been commanded to this and I submit to God. Then Imam Ali (AS) faced his eldest son and said: O’ my son, Hassan; I recommend the following to you and all of my children and members of my household and whoever this letter reaches him/her.
Never forget Divine Piety, try to the time of (your) death to remain in the religion of God [1]. All of you grab the rope of God and unite with belief in God and do not separate from each other. Indeed, I heard from the Prophet (PBUH) who said: Restoring friendly relation between people is preferred to ever praying and fasting, and the things which destroy the religion are corruption and dispute.
Fear God, fear God about the Quran, practice (the commands of) the Quran; fear God, fear God about the Salaat because Salaat is the pillar of the religion. Fear God, fear God about Ka’aba the house of your God, do not abandon Hajj, if Ka’aba remains empty and Hajj is abandoned, you will not be given time and you will be defeated by enemies. Fear God; fear God about the month of Ramadhan which the fasting in that month is a shield for the hellfire.
[1] Kafi, Vol. 7, Page 51; Nahjul Balaghah, Letter 47, Sharh Ibn Abelhadeed, Vol. 6, page 120; Tohaful Oqool, Page 197; Beharul Anwaar, Vol. 42, Page 248.
source : Shafaqna