When the Prophet ﷺ stood up following two prostrations, he would say the takbir and raise his hands until they were level with his shoulders, as he had done at the beginning of the prayer.
كَانَ النَّبِيُّ ﷺ إِذَا قَامَ مِنَ السَّجْدَتَيْنِ كَبَّرَ وَرَفَعَ يَدَيْهِ حَتَّى يُحَاذِيَ بِهِمَا مَنْكِبَيْهِ كَمَا صَنَعَ حِينَ افْتَتَحَ الصَّلاَةَ
When the Prophet ﷺ stood up following two prostrations, he would say the takbir and raise his hands until they were level with his shoulders, as he had done at the beginning of the prayer. (Using translation from Nasāʾī 1181)
كَانَ النَّبِيُّ ﷺ «إِذَا قَامَ مِنَ السَّجْدَتَيْنِ كَبَّرَ وَرَفَعَ يَدَيْهِ حَتَّى يُحَاذِي بِهِمَا مَنْكِبَيْهِ كَمَا صَنَعَ حِينَ افْتَتَحَ الصَّلَاةَ»