I saw Malik bin Huwairith saying Takbir and raising both his hands (on starting the prayers and raising his hands on bowing and also on raising his head after bowing. Malik bin Huwairith said, "Allah's Messenger (ﷺ) did the same."
Sahih al-Bukhari Book 10, Hadith 131
← Previous Hadith I saw that whenever Allah's Messenger (ﷺ) stood for the prayer, he used to raise both his hands up to the shoulders, and used to do the same on saying the Takbir for bowing and on raising his head from it and used to say, "Sami`a l-lahu liman hamidah". But he did not do that (i.e. raising his hands) in prostrations.

Sahih al-Bukhari Book 10, Hadith 130 Next Hadith → I saw Allah's Messenger (ﷺ) opening the prayer with the Takbir and raising his hands to the level of his shoulders at the time of saying the Takbir, and on saying the Takbir for bowing he did the same; and when he said, "Sami`a l-lahu liman hamidah ", he did the same and then said, "Rabbana wa laka lhamd." But he did not do the same on prostrating and on lifting the head from it."

Sahih al-Bukhari Book 10, Hadith 132