Umar bin Abi Salamah · The Book on Jana''iz (Funerals)

The Messenger of Allah said: "I had prohibited you from visiting the graves. But Muhammad was permitted to visit the grave of his mother: so visit them, for they will remind you of the Hereafter."

"The Messenger of Allah said, 'Allahu Akbar' over the deceased, so he raised his hands with the first Takbir, and he placed his right (hand) over his left."