In Genesis 3, when Adam and Eve are kicked out of the garden, it says there is a flaming sword guarding the way to the Tree of Life.
This was before Adam and Eve had any children yet.
But metalworking and forging are not mentioned until Tubal-cain -- Adam's great great great great great grandson -- comes along. Not sure if it means he invented the forging of tools or if he was just a blacksmith, though.
But back to the main point. If there was this sword guarding the way to the Tree of Life, does that mean God invented swords?