It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that when the Messenger of Allah (peace and blessings be upon him) stood up for the prayer, he raised both his hands level with his shoulders, then said the takbir. When he intended to bow, he did the same, and when he rose from the bowing, he did the same, and when he raised his head from the prostrations he did not do so.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2507