My father said, "Allah's Messenger (ﷺ) used to raise both his hands up to the level of his shoulders whenopening the prayer; and on saying the Takbir for bowing. And on raising his head from bowing heused to do the same and then say "Sami`a l-lahu liman hamidah, Rabbana wa laka l-hamd." And hedid not do that (i.e. raising his hands) in prostrations.