Abu Suhayl bin Malik narrates from his father that he said: I was with Uthman bin Affan (may Allah be pleased with him). The iqamah was called while I was talking to him about my share (a stipend to be assigned to me). I kept talking to him while he was levelling the pebbles with his sandals, until some men whom he had appointed to straighten the rows came to him and informed him that the rows had been straightened. Then he said to me: "Get straight in the row," and then he said the takbir.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2293