'Aishah (May Allah be pleased with her) reported:
Abu Bakr (May Allah be pleased with him) had a slave who brought him his earnings and Abu Bakr (May Allah be pleased with him) would eat from it. One day he brought him something and when Abu Bakr (May Allah be pleased with him) had eaten some of it, the slave asked him whether he knew where he had got that (food) from, Abu Bakr (May Allah be pleased with him) asked what it was, and he replied: I acted as a soothsayer for a man in the pre-Islamic period, and not being good at it, I deceived him; today he met me and he rewarded me for that soothsaying what you have eaten. Abu Bakr (May Allah be pleased with him) put his hand in his mouth and vomited up all that he had eaten.[Al- Bukhari].
Arabic/English book reference: Book 1, Hadith 594