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.
كَانَ رَسُولُ اللَّهِ ﷺ يَقْرَأُ وَهُوَ قَاعِدٌ فَإِذَا أَرَادَ أَنْ يَرْكَعَ قَامَ قَدْرَ مَا يَقْرَأُ إِنْسَانٌ أَرْبَعِينَ آيَةً