“From the wilderness.” Or, “desert,” the desert that they had just been on to the south of Israel. So this is a description of the land from south to north, and the western border of the Mediterranean Sea. These boundaries are very general. More detailed descriptions are given in other places (cp. Num. 34:3-12).
“the river Euphrates.” This is not the full length of the Euphrates that goes all the way to the east and turns southeast through Babylon to the Persian Gulf, but it is the northwestern branches of the Euphrates that are in Syria (Biblical Aram) (cp. Num. 34:7-15; see B. Schlegel, Satellite Bible Atlas, p. 37).
“all the land of the Hittites.” This is not the Hittite lands in central Turkey, but in Israel and in the northwestern part of the Euphrates River in Syria. The Hittites were scattered at this time and had settled in different areas.
“Great Sea.” The Mediterranean Sea.