Sahih Muslim 1044
صحيح مسلم#1044SahihAbu Mas'ud al-Ainsari reported:A person came to the Messenger of Allah (ﷺ) and said: I keep away from the morning prayer on account of such and such (a man), because; he keeps us so long. I never saw God's Messenger (ﷺ) more angry when giving an exhortation than he was that day. He said: 0 people, some of you are scaring people away. So whoever of you leads the people in prayer he must be brief, for behind him are the weak, the aged, and the people who have (argent) business to attend
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 4:206