Muwatta Imam Malik (Riwayat Yahya)

It is narrated from Malik bin Abi Amir that when Sayyiduna Uthman bin Affan, may Allah be pleased with him, would stand to deliver the sermon, he would often say—and it was very rare that he would not say this—"O people! When the Imam stands to deliver the sermon, listen to the sermon and remain silent, because whoever remains silent and does not hear the sermon will still receive the same reward as the one who remains silent and hears the sermon. And when the takbir is called for the prayer, straighten the rows and shoulders, because straightening the rows is the completion of the prayer." Then Sayyiduna Uthman Ghani, may Allah be pleased with him, would not say the opening takbir until those whom he had appointed to straighten the rows came and informed him that the rows had been straightened; then he would say the opening takbir.