Yahya related to me from Malik from his paternal uncle, AbuSuhayl ibn Malik, that his father said, "I was with Uthman ibn Affanwhen the iqama was said for the prayer and I was talking to him aboutbeing assigned a definite allowance by him. I continued talking to himwhile he was levelling some small stones with his sandals, and thensome men that he had entrusted to straighten the rows came and toldhim that the rows were straight. He said to me, 'Line up in the row,'and then he said the takbir."
USC-MSA web (English) reference: Book 9, Hadith 48
Arabic reference: Book 9, Hadith 379