Verse 15. - And at the stream of the brooks. Rather, "and the pouring (וְאֶשֶׁד) of the brooks," i.e., the slope of the watershed. Ar. עָר is an archaic form of עִיר, a city. The same place is called Ar Moab in verse 28. It was situate on the Arnon somewhat lower down than where the Israelites crossed its "brooks." The peculiarity of the site, "in the midst of the river" (Joshua 13:9, cf. Deuteronomy 2:36), and extensive ruins, have enabled travelers to identify the spot on which it stood at the junction of the Mojeb (Arnon) and Lejum (Nahaliel, verse 19). It is uncertain whether the Greeks gave the name of Areopolis, as Jerome asserts, to Ar, but in later times it was Rabbah, a town many miles further south in the heart of Moab which bore this name. Ar was at this period the boundary town of Moab, and as such was respected by the Israelites (Deuteronomy 2:9, 29).

21:10-20 We have here the removes of the children of Israel, till they came to the plains of Moab, from whence they passed over Jordan into Canaan. The end of their pilgrimage was near. They set forward. It were well if we did thus; and the nearer we come to heaven, were so much the more active and abundant in the work of the Lord. The wonderful success God granted to his people, is here spoken of, and, among the rest, their actions on the river Arnon, at Vaheb in Suphah, and other places on that river. In every stage of our lives, nay, in every step, we should notice what God has wrought for us; what he did at such a time, and what in such a place, ought to be distinctly remembered. God blessed his people with a supply of water. When we come to heaven, we shall remove to the well of life, the fountain of living waters. They received it with joy and thankfulness, which made the mercy doubly sweet. With joy must we draw water out of the wells of salvation, Isa 12:3. As the brazen serpent was a figure of Christ, who is lifted up for our cure, so is this well a figure of the Spirit, who is poured forth for our comfort, and from whom flow to us rivers of living waters, Joh 7:38,39. Does this well spring up in our souls? If so, we should take the comfort to ourselves, and give the glory to God. God promised to give water, but they must open the ground. God's favours must be expected in the use of such means as are within our power, but still the power is only of God.And at the stream of the brooks that goeth down to the dwelling of Ar,.... All that part of the country which lay upon the stream, as far as the city of Ar, the metropolis of Moab, called Ar of Moab, Isaiah 15:1,

and lieth upon the border of Moab; as that city did; so far goes the quotation out of the aforesaid book, as a proof of what was taken by the Amorites from the Moabites, and were not in their possession when Israel were upon their borders; and therefore, in taking them from the Amorites, did no wrong to Moab.