It may have been used earlier, but the first recorded instance was when Moses went to the mountaintop to talk with God. As he wandered around looking for Him, Moses didn't watch where he was going and walked right into the burning bush. Moses then yelled out, "YAHWEH!" The burning bush then spoke to Moses: "Yes, Moses, it is I, your lord God". Moses jumped back and once again exclaimed "YAHWEH!" And God replied, "That's my name, don't wear it out."
Thank you, thank you!! My name is Shecky Katz and I'll be here all week! Try the corned beef! You'll thank me afterwards!