Extreme length of the night prayer of the Prophet ﷺ

I prayed with the Prophet ﷺ one night, and he remained standing until I was about to do something bad. We said, “What were you about to do?” He said, “I was about to sit down and leave the Prophet ﷺ.”

صَلَّيْتُ مَعَ النَّبِيِّ ﷺ لَيْلَةً، فَلَمْ يَزَلْ قَائِمًا حَتَّى هَمَمْتُ بِأَمْرِ سَوْءٍ، قُلْنَا: وَمَا هَمَمْتَ؟ قَالَ: هَمَمْتَ أَنْ أَقْعُدَ وَأَذَرَ النَّبِيَّ ﷺ.

Whenever the Prophet ﷺ got up for Tahajjud prayer he used to clean his mouth (and teeth) with Siwak.

أَنَّ النَّبِيَّ ﷺ كَانَ إِذَا قَامَ لِلتَّهَجُّدِ مِنَ اللَّيْلِ يَشُوصُ فَاهُ بِالسِّوَاكِ