Abd al-Rahman al-Mas'udi (may Allah have mercy on him) said: I heard Abd al-Jabbar bin Wa'il (may Allah have mercy on him) say that the people of my household narrated to me that when Sayyiduna Wa'il (may Allah be pleased with him) came to the Messenger of Allah (peace and blessings be upon him), he saw that he (peace and blessings be upon him) would raise his hands along with the takbir, place his right hand on his left hand in the prayer, and prostrate between his two palms.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 2311