Albert Barnes Commentary Numbers 21:14

"Wherefore it is said in the book of the Wars of Jehovah, Vaheb in Suphah, And the valleys of the Arnon," — Numbers 21:14 (ASV)

Of “the book of the wars of the Lord” nothing is known except what may be gathered from the passage before us. It was apparently a collection of sacred odes commemorative of that triumphant progress of God’s people which this chapter records. From it is taken the following fragment of ancient poetry relating to the passage of the Arnon River, and probably also the Song of the Well, and the Ode on the Conquest of the Kingdom of Sihon (Numbers 21:17–18, Numbers 21:27–30).

What he did ... - The words which follow to the end of the next verse are a reference rather than a quotation. Contemporaries who had “the Book” at hand could supply the context. We can only conjecture the sense of the words, which are grammatically incomplete in the original.

The marginal reading is adopted by many and suggests a better sense: supplying a verb such as “conquered,” the words would run, “He” (that is, the Lord) “conquered Vaheb in Suphah, and the brooks, and so forth.” Suphah would thus be the name of a district remarkable for its reeds and water-flags in which Vaheb was situated.