It is narrated from Sa'id bin Sam'an that Sayyiduna Abu Hurayrah (may Allah be pleased with him) came to us in the mosque of Banu Zurayq. He said that when the Messenger of Allah (peace and blessings be upon him) began the prayer, he would raise his hands outstretched, and remain silent for a moment, asking Allah for His bounty, and when he bowed he would also say the takbir.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2316