Albert Barnes Commentary Numbers 24:21

"And he looked on the Kenite, and took up his parable, and said, Strong is thy dwelling-place, And thy nest is set in the rock." — Numbers 24:21 (ASV)

The Kenites - First mentioned (Genesis 15:19) as one of the tribes whose territory was promised to Abraham. In Judges 1:16, where we read of them as moving with the children of Judah to establish themselves in the pastures south of Arad, Moses’ father-in-law is spoken of as a Kenite . It appears therefore, since Moses’ father-in-law was a prince or priest of Midian (Exodus 2:15 and following), that the Kenites must have been of Midianite extraction, and so descended from Abraham through Keturah (Genesis 25:2).

But it seems unlikely that the Kenites of Genesis 15:19, who were to be dispossessed by the descendants of Abraham, were identical with those of whom Balaam speaks, and who were, because of help given at the time of the Exodus, always regarded as kinsmen and friends by Israel (compare 1 Samuel 15:6; 1 Samuel 27:10).

Rather, is it probable that the Kenites of Genesis 15:19 were a Canaanite people, who derived their name from the city Kain, which fell eventually within the borders of the tribe of Judah (Joshua 15:22); and that the descendants of Hobab, who appear in Judges 1:16 as making war in this very district, took possession of this city, and with it of the name Kenite also. They seem to have already done this when Balaam uttered his prediction; and in the next verse it is, as the margin correctly indicates, not of the Kenite, but of Kain the city, that he speaks.

Nor is it surprising to find them in possession of their new dwelling in the promised land, while the Israelites were still in their tents. It may well be that this roving band of Midianites had already entered Canaan, perhaps along the shores of the Dead Sea, and by routes impracticable for the huge host of Israel, and had, as a kind of advanced guard, begun the conquest of the country.

From 1 Chronicles 2:54–55, we learn that the Rechabites were a branch of the Kenites; and the name Salmaites, always given to the Kenites in the Targums, connects them with Salma, the son of Caleb, there mentioned. Jeremiah 35 shows how tenaciously, for many centuries, they held fast to the nomadic habits of their race.

Strong is thy dwellingplace, and thou puttest thy nest in a rock - Render, Strong (or firm) be thy dwelling-place, and put thou thy nest in the rock (or cliff). In the Hebrew there is a play on the words ken, “nest,” and Kain, the name of the Kenites’ dwelling. This nest in the cliff might be the city of Hazazon-tamar or Engedi, if that is (as is likely) the “city of palm-trees,” from which they went up subsequently (Judges 1:16).

But there is another site, about 10 miles south of Engedi, to which Balaam’s words would be more appropriate, on the summit of the cliff rising perpendicularly from the level of the western shore of the Dead Sea, where the city of Masada, the scene of the closing tragedy of the Jewish-Roman war, was afterward built. It is not likely that such a natural fortress would ever have been unoccupied, or even excluded from a place in the list of the cities of Judah. Nor is there any site in the Holy Land which a rude but warlike people might more fittingly designate as either Ken, the Nest, or Kain, the Possession.