It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "There is no believing servant who weeps out of fear of Allah and tears come from his eye, even if they are only the size of a fly's head, except that Allah makes him forbidden to the Fire."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9763