Biblical
The Bible relates in the Book of Genesis how God, seeking to deter Adam and Eve from returning to the Garden of Eden, "placed at the east of the garden of Eden Cherubim and a flaming sword which turned every way." By some accounts, the Cherubim are replaced with the Archangel Michael, who wields a similar weapon. King David was given the sword of the slain giant Goliath by the priest Ahimelech, to which was attached extra-biblical mythology and traditions. In the Book of Revelation, Jesus is symbolically described wielding a double-edged sword that proceeds out from his mouth, in reference to the "sword of the spirit" which is the "word of truth".
Read more about this topic: Magic Sword