The Book of Leading the Prayer (Al-Imamah)
10/35. Chapter:
The Imam should make the prayer short
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ أَخَفَّ النَّاسِ صَلاَةً فِي تَمَامٍ .
It was narrated from Anas that the Prophet (ﷺ) used to make his prayer very brief but still complete when leading people.
Reference : Sunan an-Nasa'i 824In-book reference : Book 10, Hadith 48English translation : Vol. 1, Book 10, Hadith 825