Musnad Abu Ya'la al-Mawsili 155:18

Al-Hasan ibn Hammad Sajjadah narrated to us, Yahya ibn Ya'la narrated to us, from Yazid ibn Sinan ibn Abi Farwah, from al-Zuhri, from Sa'id ibn al-Musayyib, from Abu Hurayrah: That the Prophet (peace and blessings of Allah be upon him) prayed over a funeral, and he said the takbir, then he placed his right hand upon his left hand.