This tradition has also been transmitted by Rifa’ah b Rafi through a different chain of narrators. This version has:

When you get up to pray, say the takbir, exalting Allah; then recite the Qur’an as much as it is convenient for you. The version adds: When you sit in the middle of the prayer, do it completely(so that you are at rest) and spread your left thigh; then recite the tashahhud. Then if you get up (again), do in a similar way until you finish your prayer.

حَدَّثَنَا مُؤَمَّلُ بْنُ هِشَامٍ، حَدَّثَنَا إِسْمَاعِيلُ، عَنْ مُحَمَّدِ بْنِ إِسْحَاقَ، حَدَّثَنِي عَلِيُّ بْنُ يَحْيَى بْنِ خَلاَّدِ بْنِ رَافِعٍ، عَنْ أَبِيهِ، عَنْ عَمِّهِ، رِفَاعَةَ بْنِ رَافِعٍ عَنِ النَّبِيِّ ﷺ بِهَذِهِ الْقِصَّةِ قَالَ " إِذَا أَنْتَ قُمْتَ فِي صَلاَتِكَ فَكَبِّرِ اللَّهَ تَعَالَى ثُمَّ اقْرَأْ مَا تَيَسَّرَ عَلَيْكَ مِنَ الْقُرْآنِ " . وَقَالَ فِيهِ " فَإِذَا جَلَسْتَ فِي وَسَطِ الصَّلاَةِ فَاطْمَئِنَّ وَافْتَرِشْ فَخِذَكَ الْيُسْرَى ثُمَّ تَشَهَّدْ ثُمَّ إِذَا قُمْتَ فَمِثْلَ ذَلِكَ حَتَّى تَفْرُغَ مِنْ صَلاَتِكَ " .