Sahih al-Bukhari 704
صحيح البخاري#704Sahihحَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، حَدَّثَنَا سُفْيَانُ، عَنْ إِسْمَاعِيلَ بْنِ أَبِي خَالِدٍ، عَنْ قَيْسِ بْنِ أَبِي حَازِمٍ، عَنْ أَبِي مَسْعُودٍ، قَالَ قَالَ رَجُلٌ يَا رَسُولَ اللَّهِ إِنِّي لأَتَأَخَّرُ عَنِ الصَّلاَةِ فِي الْفَجْرِ مِمَّا يُطِيلُ بِنَا فُلاَنٌ فِيهَا. فَغَضِبَ رَسُولُ اللَّهِ صلى الله عليه وسلم مَا رَأَيْتُهُ غَضِبَ فِي مَوْضِعٍ كَانَ أَشَدَّ غَضَبًا مِنْهُ يَوْمَئِذٍ ثُمَّ قَالَ " يَا أَيُّهَا النَّاسُ إِنَّ مِنْكُمْ مُنَفِّرِينَ، فَمَنْ أَمَّ النَّاسَ فَلْيَتَجَوَّزْ، فَإِنَّ خَلْفَهُ الضَّعِيفَ وَالْكَبِيرَ وَذَا الْحَاجَةِ ".
Narrated Abu Mas`ud:A man came and said, "O Allah's Messenger (ﷺ)! I keep away from the morning prayer because so-and-so (Imam) prolongs it too much." Allah's Messenger (ﷺ) became furious and I had never seen him more furious than he was on that day. The Prophet (ﷺ) said, "O people! Some of you make others dislike the prayer, so whoever becomes an Imam he should shorten the prayer, as behind him are the weak, the old and the needy
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 10:99