This verse repeats what the first part of verse 1 says.

No inheritance among their brethren: it is strange that Revised Standard Version here has brethren, whereas in 10.9 it has “brothers.” Unlike the other tribes of Israel, the tribe of Levi was not assigned any territory. For inheritance see “inherit” in 1.38.

The LORD is their inheritance, as he promised them: see 10.9. This is more clearly expressed by Good News Translation: “their share is the privilege of being the LORD’s priests.” The Contemporary English Version model is also helpful: “because he has promised to provide for them in this way.”

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .