It is narrated from Sayyiduna Ali bin Abi Talib (may Allah be pleased with him) that when the Messenger of Allah (peace and blessings be upon him) stood for the obligatory prayer, he would say the takbir and raise both hands to his shoulders; when he completed the recitation and intended to bow, he would also do so; when he raised his head from bowing, he would do the same; he would not raise his hands while in the sitting position; and when he stood up from the two prostrations, he would say the takbir and raise his hands in the same way.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2817