Sunan an-Nasa'i 791
سنن النسائي#791SahihIt was narrated that Anas said:"The Iqamah for prayer was said, and the Messenger of Allah (ﷺ) was conversing privately with a man, and did not commence the prayer until the people slept
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih - Agreed Upon
In-book reference: 10:15