(a) It is narrated from Sayyiduna Abdullah bin Umar bin al-Khattab (may Allah be pleased with them both) that he said: I saw the Messenger of Allah (peace and blessings be upon him): when he (peace and blessings be upon him) began the prayer, he would say the takbir and raise his hands up to his shoulders. Then when he said the takbir for bowing he would do the same; then when he said 'Sami' Allahu liman hamidah' (Allah has heard the one who praises Him) he would do the same, and he would say 'Rabbana wa lakal-hamd' (Our Lord, and to You belongs all praise); but when he prostrated and when he rose from prostration, he did not raise his hands.
(b) In the narration of Malik and Ibn Uyaynah there is that when he (peace and blessings be upon him) began the prayer, he would raise his hands. This narration has the same meaning as the narration of Shu'ayb, but the narration of Shu'ayb is clearer.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2310