Sunan Abi Dawud Book 2, Hadith 154
the Iqamah was pronounced (for the night prayer) and the Messenger of Allah (ﷺ) remained engaged in talking (to a person) in the corner of the mosque. He did not begin prayer until the people slept.
we stood for praying at Mina when the Imam had not come out. Some of us sat down (and I too). An old man from Kufah said to me: Why did you down? I said : Ibn Buraidah, this is Sumud (i.e., waiting for the Imam in the standing condition). The old man then narrated a tradition from ‘Abd al-Rahman b. ‘Awaajah on the authority of al-Bara’ b. ‘Azib: We would stand in rows during the time of the Messenger of Allah (ﷺ) for a long time before he pronounced Takbir. He further said; Allah, the Exalted and Mighty, sends blessings and the angles invoke blessings for those who are nearer to the front rows. No step is more liking to Allah than a step which one takes to join the row (of the prayer).
when the Iqamah was pronounced and the Messenger of Allah (ﷺ) saw that they (the people) were small in number, he would sit down, nd would not pray; but when he saw them (the people) large in number, he would pray.