My favorite one :)
A fool consoling a man on his brothers's death said "May Allah give you a big reward and have mercy on your brother and save him from the questions of Gog and Magog". All those present noticed his mistake and began to laugh at him and asked "Is it Gog and Magog that will question?" He replied "May Allah curse the devil, my tongue slipped. I wanted to say Harooth and Marooth".