It is narrated from Sayyiduna Khuzaymah bin Thabit (may Allah be pleased with him) that he saw (in a dream) as though he were prostrating on the forehead of the Prophet (peace and blessings be upon him). So he came to the Prophet (peace and blessings be upon him) and told him, and the Prophet (peace and blessings be upon him) said to him: "Sit down and prostrate, and do just as you saw."
Hadith Referenceالمعجم الكبير للطبراني / باب الخاء / 3702