question #3 Sahih Muslim 731c, Book 6, Hadith 136 : What is the duration of recitation before bowing in the Tahajjud prayer as practiced by the Prophet (ﷺ)?

The Messenger of Allah (ﷺ) used to recite in sitting position (while observing the Tahajjud prayer) and when he intended to bow, he would stand up and recite (for the duration in which) a man (ordinarily) recites forty verses.