It was narrated from ‘Ali bin Abi Talib ؓ that when the Messenger of Allah ﷺ stood up to offer the prescribed prayer, he would say Allahu Akbar and raise his hands to shoulder height; he did the same when he finished reciting and wanted to bow, and he did it when he raised his head from bowing. He did not raise his hands when sitting in any part of his prayer, but when he stood up following the two prostrations, he raised his hands in the same manner and said Allahu Akbar. (Using translation from Aḥmad 717)
عَنْ رَسُولِ اللهِ ﷺ أَنَّهُ كَانَ إِذَا قَامَ إِلَى الصَّلَاةِ الْمَكْتُوبَةِ كَبَّرَ وَرَفَعَ يَدَيْهِ حَذْوَ مَنْكِبَيْهِ وَيَصْنَعُ مِثْلَ ذَلِكَ إِذَا قَرَأَ قِرَاءَتَهُ وَأَرَادَ أَنْ يَرْكَعَ وَيَصْنَعُهُ إِذَا فَرَغَ مِنَ الرُّكُوعِ وَلَا يَرْفَعُ يَدَيْهِ فِي شَيْءٍ مِنْ صَلَاتِهِ وَهُوَ قَاعِدٌ وَإِذَا قَامَ مِنَ السَّجْدَتَيْنِ رَفَعَ يَدَيْهِ كَذَلِكَ وَكَبَّرَ وَقَدْ رُوِّينَا هَذَا الْحَدِيثَ عَنْ أَبِي مُوسَى الْأَشْعَرِيِّ وَجَابِرِ بْنِ عَبْدِ اللهِ الْأَنْصَارِيِّ وَأَبِي هُرَيْرَةَ وَأَنَسِ بْنِ مَالِكٍ عَنِ النَّبِيِّ ﷺ