Rishi Ved Vyas and Lord Ganesha

Legend has it that sage Vyasa came to Lord Ganesha to ask for help. He wanted Ganesha to transcribe the entire epic of the Mahabharata for him, upon which Ganesha agreed but on one condition!

 He told Vyasa to keep reciting the verses without any pause. Now Vyasa knew Ganesha's speed, so to avail himself a break, he told Ganesha that he will have to understand every verse before he writes it down!

This way, whenever Vyasa needed a break, he would throw in a rather difficult verse. That way, he would get sufficient time to think about his next verse!

Thus Rishi Ved Vyas composed the Mahabharata while Lord Ganesha wrote it!