vine of Sibmah - near Heshbon: namely, languishes.
lords of ... heathen - The heathen princes, the Assyrians, etc., who invaded Moab, destroyed his vines. So Jeremiah in the parallel place (Jer 48:32, Jer 48:33). Maurer thinks the following words require rather the rendering, “Its (the vine of Sibmah) shoots (the wines got from them) overpowered (by its generous flavor and potency) the lords of the nations” (Gen 49:11, Gen 49:12, Gen 49:22).
come ... Jazer - They (the vine shoots) reached even to Jazer, fifteen miles from Heshbon.
wandered - They overran in wild luxuriance the wilderness of Arabia, encompassing Moab.
the sea - the Dead Sea; or else some lake near Jazer now dry; in Jer 48:32 called “the sea of Jazer”; but see on Jer 48:32 (Psa 80:8-11).