It is narrated from Abu Wa'il that Sayyiduna Ammar bin Yasir (may Allah be pleased with him) delivered a sermon to us that was extremely eloquent and brief. We said: O Abu al-Yaqzan! You have spoken very comprehensively and briefly. He said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Indeed, the lengthiness of a man's prayer and the brevity of his sermon are a sign of his understanding (fiqh). So lengthen the prayer and keep the sermon short." This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it with this wording!