Sahih Muslim Book - 4, Hadith - 862

حَدَّثَنِي مُحَمَّدُ بْنُ رَافِعٍ حَدَّثَنَا عَبْدُ الرَّزَّاقِ أَخْبَرَنَا ابْنُ جُرَيْجٍ حَدَّثَنِي ابْنُ شِهَابٍ عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ أَنَّ ابْنَ عُمَرَ قَالَ كَانَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ إِذَا قَامَ لِلصَّلَاةِ رَفَعَ يَدَيْهِ حَتَّى تَكُونَا حَذْوَ مَنْكِبَيْهِ ثُمَّ كَبَّرَ فَإِذَا أَرَادَ أَنْ يَرْكَعَ فَعَلَ مِثْلَ ذَلِكَ وَإِذَا رَفَعَ مِنْ الرُّكُوعِ فَعَلَ مِثْلَ ذَلِكَ وَلَا يَفْعَلُهُ حِينَ يَرْفَعُ رَأْسَهُ مِنْ السُّجُودِ.

It was narrated from Salim bin 'Abdullah that Ibn 'Umar said: "When the Messenger of Allah (s.a.w) stood up to offer Salat, he would raise his hands until they were level with his shoulders, then he would say the Takbir. When he wanted to bow, he did that, and when he rose from bowing he did that, but he did not do that when he lifted his head from prostrating."