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  

When the Prophet of Allah ﷺ started to pray, he raised his hands, and when he bowed, he did likewise, and when he raised his head from bowing he did likewise, and when he raised his head from prostration, he did likewise, meaning he raised his hands.  

أَنَّ نَبِيَّ اللَّهِ ﷺ كَانَ إِذَا دَخَلَ فِي الصَّلاَةِ رَفَعَ يَدَيْهِ وَإِذَا رَكَعَ فَعَلَ مِثْلَ ذَلِكَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ فَعَلَ مِثْلَ ذَلِكَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ السُّجُودِ فَعَلَ مِثْلَ ذَلِكَ كُلَّهُ يَعْنِي رَفْعَ يَدَيْهِ  

It was narrated that Malik bin Huwairith said that when the Messenger of Allah ﷺ said Allahu Akbar, he would raise his hands until they were close to his ears; when he bowed in Ruku’ he did likewise, and when he raised his head from Ruku’ he did likewise. (Using translation from Ibn Mājah 859)  

أَنَّ رَسُولَ اللهِ ﷺ كَانَ إِذَا كَبَّرَ رَفَعَ يَدَيْهِ حَتَّى يَجْعَلَهُمَا قَرِيبًا مِنْ أُذُنَيْهِ وَإِذَا رَكَعَ صَنَعَ مِثْلَ ذَلِكَوَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ فَعَلَ مِثْلَ ذَلِكَ  

I saw the Messenger of Allah ﷺ when he said the opening Takbir of the prayer, raise his hands until they were level with his shoulders. When he said the Takbir before bowing he did likewise, and when he said: 'Sami Allahu liman hamidah (Allah hears those who praise Him),' he did likewise, then he said: 'Rabbana wa lakal-hamd (Our Lord, to You be praise).' But he did not do that when he prostrated or when he raised his head from prostration. (Using translation from Nasāʾī 876)   

كَانَ النَّبِيُّ ﷺ إِذَا افْتَتَحَ الصَّلَاةَ رَفَعَ يَدَيْهِ حَذْوَ مَنْكِبَيْهِ فَإِذَا رَكَعَ فَعَلَ مِثْلَ ذَلِكَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ فَعَلَ مِثْلَ ذَلِكَ وَقَالَ «سَمِعَ اللَّهُ لِمَنْ حَمِدَهُ اللَّهُمَّ رَبَّنَا وَلَكَ الْحَمْدُ» وَلَا 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