Musannaf Ibn Abi Shaybah 12415 — What lightens the punishment

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) passed by a grave and stood by it, then said: "Bring me two palm stalks." Then he (peace and blessings be upon him) planted one palm stalk by its head and the other by its feet. It was said: "O Messenger of Allah (peace and blessings be upon him), will this benefit him?" He (peace and blessings be upon him) said: "Perhaps some of the punishment of the grave will be lightened because of them, as long as moisture remains in them (as long as they are fresh)."