Mishkat al-Masabih #2057

Ibn ‘Abbās said that one of the Prophet's companions set up his tent over a grave without realising that it was a grave, and it contained a man who was reciting the sūra, “Blessed is He in whose hand is the kingdom,” up to the end. He went and told the Prophet, who said, “It is the defender; it is the protector which is protecting him from God's punishment.” Tirmidhi transmitted it, .saying this is a gharīb tradition.