Musannaf Ibn Abi Shaybah 37942 — The words of al-Hasan al-Basri

It is narrated from al-Hasan that he said: Whoever goes to a graveyard and says: O Allah, Lord of the decayed bodies and of the decayed bones which left the world believing in You, send down upon them mercy from You and peace from me, then every believer who has died since the creation of Adam seeks forgiveness for that man.