“The Book of the Wars of the LORD”
Therefore it is stated in the Book of the Wars of the LORD: 'Waheb in Suphah and the wadis of the Arnon,' (Numbers 21:14 BSB)
What it sounds like today
A citation of some book we assume is part of the Bible.
The cultural key
This brief quotation opens a small window onto Israel's lost literature. 'The Book of the Wars of the LORD' was evidently an ancient anthology, probably of poems and victory songs celebrating God's battles on Israel's behalf, that once circulated and that the author of Numbers quotes here as a known source. It no longer exists; only this snippet survives. It is not the only such lost book named in Scripture: the 'Book of Jashar' is cited in Joshua and 2 Samuel, and the historical books repeatedly refer to now-vanished royal chronicles. Far from embarrassing, these citations show that the biblical writers were working with, quoting, and preserving pieces of a broader national literature, much as a historian cites earlier sources. A modern reader assumes any book the Bible names must be a book of the Bible; in fact this is a lost ancient work the Scripture quotes and thereby partly preserves.
Recovered meaning
Numbers quotes 'the Book of the Wars of the LORD,' a now-lost ancient collection of victory songs about God's battles. Like the Book of Jashar, it shows Israel had a wider literature that the biblical authors drew on and quoted.