Deuteronomy 33:28 - Joseph Benson’s Commentary on the Old and New Testaments

Israel shall dwell in safety alone Either, 1st, In safety, although 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, 2d, Distinct and separated from all other nations, with whom I will not have them to mingle themselves. The fountain That is, the posterity of Jacob, which flowed from him as waters from a copious fountain, in great abundance. So the expression is used Psalms 68:26. The fountain is here put for the river, or streams which flow from it, as Jacob, or Israel, who is the fountain, is often put for the children of Israel. The Hebrew word, however, which we render fountain, often signifies an eye, and the sense here may be, The eye of Jacob shall look upon a land of corn, &c. Also his heavens shall drop down dew That is, those heavens, or that air which hangs over his land, shall water it with refreshing dews, and render it fruitful in corn, wine, and other products of a most fertile country. Thus Moses confirms to Jacob's seed the blessing which Isaac gave to Jacob himself, Genesis 27:28.