Musannaf Ibn Abi Shayba 29:43

Ibn Idris narrated to us, from Hanash ibn al-Harith, from his father, who said: The [tribe of] Nakha‘ passed by Umar. He made them stand and inspected them, and they were two thousand and five hundred, and over them was a man called Arta’ah. He said: "I see nobility settled among you. March to your brothers from the people of Iraq." They said: "Rather, we will march to al-Sham." He said: "March to Iraq." They said: "There is no compulsion in religion." He said: "March to Iraq." When they arrived in Iraq, they began to drag the dowry and slaughter it. He wrote to them: "Reform, for there is a refuge or a soul in the matter." And I heard Abu Bakr ibn Ayyash saying: The Banu Asad on the day of al-Qadisiyyah were four hundred, and Bajilah were three thousand, and the Nakha‘ were two thousand and three hundred, and Kindah were like the Nakha‘, and they were all ten thousand. And there was no one among the people less than Misr. I heard Abu Bakr [saying] that Umar favored them, so he gave some of them two thousand and some of them six hundred. And Abu Bakr ibn Ayyash mentioned regarding His saying: "Allah will bring a people He loves and who love Him," he said: "The people of al-Qadisiyyah." Narrated to us...