Ibn Maysarah bin Halbas (may Allah have mercy on him) narrates: I heard Sayyiduna Wathilah bin al-Asqa' (may Allah be pleased with him) say: I heard the Messenger of Allah (peace and blessings be upon him) make this supplication in the funeral prayer of a Muslim man: "O Allah, so-and-so is under Your protection and in the shelter of Your nearness, so save him from the trial of the grave and the punishment of Hell; indeed You are the One of faithfulness and truth. O Allah, forgive him and have mercy on him; indeed You alone are the Oft-Forgiving, the Most Merciful."
Hadith Referenceالمعجم الكبير للطبراني / باب الواو / 18434