Narrated 'Ammar bin Yasir (RA):

He heard Allah's Messenger (ﷺ) say: "The length of a man's prayer and the shortness of his Khutbah (religious talk) are a sign of his understanding (of the religion)." [Reported by Muslim].

وَعَنْ عَمَّارِ بْنِ يَاسِرٍ رَضِيَ اَللَّهُ عَنْهُمَا قَالَ: سَمِعْتُ رَسُولَ اَللَّهِ ‏- صلى الله عليه وسلم ‏-يَقُولُ: { إِنَّ طُولَ صَلَاةِ اَلرَّجُلِ, وَقِصَرَ خُطْبَتِهِ مَئِنَّةٌ مِنْ فِقْهِهِ } رَوَاهُ مُسْلِمٌ .‏ [1]‏ .‏