In Sermon (132), Imam Ali (peace be upon him) advised Umar ibn al-Khattab regarding participation in the campaign against Rome. This sermon comes at a time when Muslims were facing various challenges, and it was crucial to bolster their strength. Imam Ali emphasized that Allah has taken the responsibility of protecting the believers and their faith.

One of the main themes in this sermon is the assurance of Allah's support for the believers, regardless of their numerical strength. Imam Ali highlighted that even when Muslims were few, Allah safeguarded them against their enemies. This serves as a spiritual reminder that believers should rely on Allah's power rather than their own numbers.

Imam Ali also cautioned that if Umar were to confront the enemies directly and fall into calamity, there would be no safe place left for the Muslims to retreat to. This underscores the importance of exercising caution in leadership. Leaders must always consider the consequences of their decisions.

Finally, Imam Ali advised sending an experienced person to the battlefield instead of going himself. This indicates that strategic planning and the selection of capable individuals are vital for success. This sermon teaches us the importance of having faith in Allah's support and making wise decisions.