Ayyub bin Bashir narrates from his father, Sayyiduna Bashir (may Allah be pleased with him), who said: There was a dispute among Banu Mu'awiyah, so the Prophet (peace and blessings be upon him) went to make peace between them. He (peace and blessings be upon him) looked towards a grave and said: "May you not know." He (peace and blessings be upon him) was asked about it, and he (peace and blessings be upon him) said: "This one was asked about me, and he said: I do not know."
Hadith Referenceالمعجم الكبير للطبراني / باب الباء / 1226