The Book of the Commencement of the Prayer
11/86. Chapter:
Raising the hands parallel to the shoulders before bowing
Sunan an-Nasai
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ سَالِمٍ، عَنْ أَبِيهِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم إِذَا افْتَتَحَ الصَّلاَةَ يَرْفَعُ يَدَيْهِ حَتَّى يُحَاذِيَ مَنْكِبَيْهِ وَإِذَا رَكَعَ وَإِذَا رَفَعَ رَأْسَهُ مِنَ الرُّكُوعِ .
It was narrated from Salim that: His father said: "I saw the Messenger of Allah (ﷺ) when he started to pray, raise his hands until they were parallel to his shoulders, (and he did that) when he bowed and when he raised his head from bowing."
Reference : Sunan an-Nasa'i 1025In-book reference : Book 11, Hadith 150English translation : Vol. 2, Book 11, Hadith 1026