Sayyiduna Abu Hurayrah (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "By the One in whose hand is my soul! If you knew what I know, you would weep much and laugh little."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الأيمان / 19809