Sahih al-Bukhari 6110
صحيح البخاري#6110SahihNarrated Abu Mas`ud:A man came to the Prophet (ﷺ) and said "I keep away from the morning prayer only because such and such person prolongs the prayer when he leads us in it. The narrator added: I had never seen Allah's Apostle more furious in giving advice than he was on that day. He said, "O people! There are some among you who make others dislike good deeds) cause the others to have aversion (to congregational prayers). Beware! Whoever among you leads the people in prayer should not prolong it, because among them there are the sick, the old, and the needy." (See Hadith No. 670, Vol)
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 78:137