I saw the Prophet ﷺ raise his hands when he uttered the takbir (Allah is most great), when he bowed and when he raised his head after bowing until he brought them to the lobes of his ears. (Using translation from Abū Dāʾūd 745)  

رَأَيْتُ رَسُولَ اللهِ ﷺ «يَرْفَعُ يَدَيْهِ إِذَا كَبَّرَ وَإِذَا رَكَعَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ حَتَّى بَلَغَتَا فُرُوعَ أُذُنَيْهِ»