I used to observe prayer with the Messenger of Allah ﷺ and his prayer was of moderate length and his sermon too was of moderate length.
كُنْتُ أُصَلِّي مَعَ النَّبِيِّ ﷺ الصَّلَوَاتِ فَكَانَتْ صَلاَتُهُ قَصْدًا وَخُطْبَتُهُ قَصْدًا وَفِي رِوَايَةِ أَبِي بَكْرٍ زَكَرِيَّاءُ عَنْ سِمَاكٍ