Ibn Jarir said: A group from among the Kurds had joined with a group from among the Persians. Abu Musa encountered them in the lands of Bayruz near the Tira (Tiri?) river, attacked them, and pursued them as far as Isfahan. In the battle fought with them, he left Re-bi b. Ziyad as commander in his place. After his brother Muhajir was killed, Rebi began to command the battle against them. The battle turned in favor of the Muslims, intensified, and Allah—the Exalted—defeated the disbelievers (kāfir). All praise and gratitude belong to Allah. Indeed, defeating the disbelievers (kāfir) is a law (sunnah) that Allah—the Exalted—applies to His servants and to the successful supporters who follow the prophets. One fifth of the spoils obtained after the battle was set aside, and this portion, along with the good news of the conquest, was sent to ʿUmar. Dabbe b. Mihsan al-Anzī also went to Medina and complained about Abu Musa to ʿUmar, relating some of his actions that warranted punishment. ʿUmar summoned Abu Musa to Medina and questioned him about these matters. He defended himself by presenting acceptable excuses. ʿUmar found his defense appropriate and sent him back to his post.
He also found Dabbe justified in his complaint. While Abu Musa continued his role as imam in Basra, ʿUmar passed away.