After the conquest of Basra Imam Ali (a) wrote the following letter to the citizens of Kufa.
O' Citizens of Kufa! May the Merciful Lord reward you on His behalf and on behalf of the Ahlul Bayt (Progeny of the Holy Prophet) (a) for obeying their orders and coming to their help. May He reward you more handsomely than He rewards those who obey His commands (because you followed the true path against very heavy odds and in spite of alluring enticements).
You have done your duty. You heard the call of your Amir, responded to it; he called you and you obeyed his orders with zeal and enthusiasm.