Of what date is the oldest inscription of Yahweh found? Is it true that there is an inscription of Yahweh found that is older than when Moses was revealed the name of God in the Bible?
Tradition holds that Moses lived sometime around the 15th century B.C. This would put the oldest use of the tetragrammaton (the Hebrew word "YHWH", anglicized to "Yahweh") to the same time frame, as Moses wrote the oldest portions of the Bible.

Outside the Bible, the oldest known inscription of the tetragrammaton appears on the Mesha stele, which has been dated to around 840 B.C. You can read more about the Mesha stele here.