Alone; 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 Numbers 23:9 Ezra 9:1,2. The fountain of Jacob, i.e. the posterity of Jacob, which flowed from him its waters from a fountain, in great abundance. Compare Psalms 68:26 Isaiah 48:1. The fountain is here put for the river or streams which flow from it, as Psalms 94:10; as the root is put for the branch, 2 Chronicles 22:10 Isaiah 11:10 Revelation 5:5; and as Jacob 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 Jacob, i.e. of the people of Israel; and so the sense is, They who now only 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 Psalms 4:6, Psalms 27:13 34:12 Ecclesiastes 2:1, Ecclesiastes 3:13. His heavens, i.e. those heavens or that air which hangs over his land.