(a) It is narrated from Salim bin Abdullah (may Allah have mercy on him) that Ibn Umar (may Allah be pleased with them both) said that when the Messenger of Allah (peace and blessings be upon him) stood for the prayer, he would raise his hands until they were level with his shoulders, then say the takbir; and when he intended to bow he would do the same; and when he raised his head from bowing he would do the same; and when he raised his head from prostration he would not do so.
(b) In the narration of Muhammad bin Amr bin Halhalah (may Allah have mercy on him) there is that when he (peace and blessings be upon him) said the takbir, he would raise his hands up to his shoulders.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2314