'Ammar bin Yasir (May Allah be pleased with them) reported:
I heard Messenger of Allah (ﷺ) saying, "Prolonging Salat (prayer) and shortening the Khutbah (religious talk) indicate the religious knowledge of the person. Make your Salat long and your sermon short."[Muslim].
App reference: Book 2, Hadith 20
Arabic/English book reference: Book 2, Hadith 700