Hadith on Moderation: The Prophet’s prayer and sermon were of moderate length, not too long or too short
Jabir ibn Samurah reported: I was praying with the Messenger of Allah, peace and blessings be upon him, and his prayer was of moderate length and his sermon was of moderate length.
Source: Sahih Muslim 866
Grade: Sahih (authentic) according to Muslim
عَنْ جَابِرِ بْنِ سَمُرَةَ قَالَ كُنْتُ أُصَلِّي مَعَ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ فَكَانَتْ صَلَاتُهُ قَصْدًا وَخُطْبَتُهُ قَصْدًا
866 صحيح مسلم كِتَاب الْجُمُعَةِ باب تَخْفِيفِ الصَّلَاةِ وَالْخُطْبَةِ