Musnad Ahmad Hadith 4674

It is narrated from Ibn Umar (may Allah be pleased with them both) that the Noble Prophet (ﷺ) used to raise his hands to the level of his shoulders at the beginning of the prayer, and he would also raise his hands when going into bowing (ruku‘) and after raising his head from bowing. And the Noble Prophet (ﷺ), after saying "Sami‘ Allahu liman hamidah," would say "Rabbana wa laka al-hamd." However, between the two prostrations, the Noble Prophet (ﷺ) did not raise his hands.