that when the Messenger of Allah ﷺ started to pray, he would raise his hands in level with his shoulders, and when he bowed and when he raised his head from bowing, he would raise them likewise and say "Sami Allahu liman hamidah, Rabbana wa lakal-hamd (Allah hears those who praise Him, our Lord, to You be praise." And he did not do that when he prostrated.  

أَنَّ رَسُولَ اللَّهِ ﷺ كَانَ إِذَا افْتَتَحَ الصَّلاَةَ رَفَعَ يَدَيْهِ حَذْوَ مَنْكِبَيْهِ وَإِذَا رَكَعَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ رَفَعَهُمَا كَذَلِكَ وَقَالَ سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ رَبَّنَا وَلَكَ الْحَمْدُ وَكَانَ لاَ يَفْعَلُ ذَلِكَ فِي السُّجُودِ  

My father said, "Messenger of Allah ﷺ used to raise both his hands up to the level of his shoulders when opening the prayer; and on saying the Takbir for bowing. And on raising his head from bowing he used to do the same and then say "Samiʿa l-lahu liman hamidah, Rabbana wa laka l-hamd." And he did not do that (i.e. raising his hands) in prostrations. (Using translation from Bukhārī 735)  

أَنَّ رَسُولَ اللهِ ﷺ كَانَ إِذَا افْتَتَحَ الصَّلَاةَ رَفَعَ يَدَيْهِ حَذْوَ مَنْكِبَيْهِ وَإِذَا رَكَعَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ رَفَعَهُمَا كَذَلِكَ وَقَالَ «سَمِعَ اللهُ لِمَنْ حَمِدَهُ رَبَّنَا وَلَكَ الْحَمْدُ» وَكَانَ لَا يَفْعَلُ ذَلِكَ فِي السُّجُودِ  

[Machine] The Prophet ﷺ used to raise his hands parallel to his shoulders when he entered prayer, and when he bowed, and when he lifted his head from the bow, and likewise...  

أَنَّ رَسُولَ اللهِ ﷺ كَانَ إِذَا دَخَلَ فِي الصَّلَاةِ رَفَعَ يَدَيْهِ حَذْوَ مَنْكِبَيْهِ وَإِذَا رَكَعَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ وَكَذَلِكَ