Jahwist
The Jahwist, or Yahwist, often abbreviated J, is one of the sources of the Pentateuch (Torah), together with the Deuteronomist, the Elohist and the Priestly source. It's probably the oldest of the four. It gets its name from the fact that it characteristically uses the term Yahweh (German Jahwe, Hebrew YHWH) for God in the book of Genesis.