Detailed Explanation — Letter (56): When Shareeh Ibn Hani was appointed as the leader of the army (Muqadmat al-Jish) ahead of the army going to Syria, he was given this instruction.

This letter reflects the wisdom and insight of Imam Ali (a.s.) when he appointed Shareeh Ibn Hani as the leader of the army heading to Syria. The context of this letter is during the period of the expansion of the Islamic Caliphate, where Imam Ali (a.s.) felt the necessity to provide spiritual and moral guidance to his commanders.

The main theme of this letter is the fear of Allah and the caution against the deceitful nature of the world. Imam Ali (a.s.) emphasizes the importance of having equal fear of Allah in the morning and evening, which should be a fundamental part of a believer's daily life. This instruction highlights that remembrance of Allah is essential for seeking His pleasure at every moment.

He also makes it clear that one must be wary of the deceptions of the worldly life. Awareness of the transitory nature of worldly existence and its allure encourages individuals to control their desires. Additionally, he advises the suppression of one's anger, which is a significant aspect of human psychology.

A crucial point in this letter is that if a person follows their desires without restraint, they may fall into many harms. This serves as a spiritual lesson that one must control their desires to stay on the right path.

Practically, this letter teaches us that the fear of Allah and the effort to avoid the deceptions of the world can bring peace and contentment to our lives. We should strive to control our desires and practice patience, especially in moments of anger.