Matthew Poole and continuators on Deuteronomy 33:28

28 Israel then shall dwell in safety alone ; the fountain of Jacob shall be upon a land of corn and wine: also his heavens shall drop down dew.

Either 1. Though they be alone, and have no confederates to defend them, but have all the world against them, yet my single protection shall be sufficient for them. Or 2. Distinct and separated from all other nations, with whom I will not have them to mingle themselves. See Num. 23. 9. Ezra 9. 1, 2.

(i. e.) The posterity of Iacob, which flowed from him as waters from a Fountain, in great abundance. Compare Psal. 68. 26. Isa. 48. 1. The fountain is here put for the River or Streams which flow from it, as Psal. 104. 10. as the Root is put for the branch. 2 Chron. 22. 10. Isa. 11. 10. Revel. 5. 5. and as Iacob or Israel who is the fountain, is oft put for the children of Israel. Or the eye (for so the Hebrew word oft signifies) of Iacob, i. e. of the people of Israel, and so the sense is, They who now onely hear of the Land of promise shall shortly see it, which I am not suffered to do, and shall enjoy it, which is oft signified by seeing, as Psal. 4. 6. and 27. 13. and 34. 13. Eccles. 2. 1. and 3. 13.

(i. e.) Those Heavens or that Air which hangs over his Land.

Marginal references: Jer. 23. 6.