Musa Ku Taghi

The legend of 'Musa Ku Taghi' has been heard among people of Khorasan (located in the eastern part of Iran). The story is about three brothers named Musa, Taghi, and karim. One day they decided to go outside to play without asking their parents for permission. Taghi goes missing. Musa and Karim prayed to God to turn one of them into a bird so that he can fly up in the skies and look for their brother while the other one returns home and explains the situation to their parents. 

God answered their prayers and turned Karim into a bird. He flew up but couldn't find their brother so he  kept asking Musa about Taghi, saying "Musa Ku Taghi" (which means, 'Musa, where is Taghi?'). The sound of him asking is now recognized as tweeting.