Isaiah 40:28 - Matthew Poole's English Annotations on the Holy Bible

Of the ends of the earth; of all the earth, and the inhabitants thereof, from one end to another. He seems to mention the ends or utmost bounds, because they might seem to be more out of the reach and care of God's providence, as being most remote from Jerusalem, the only place of God's solemn and public worship in the world, and being then thought to be uninhabited. The argument is clear and strong: God, who made all, even the most desolate and barbarous parts of the earth, and consequently takes care of them, will not neglect his own land and people. Fainteth not, neither is weary; he is not by age or hard labour become weak and unable to help his people, as men are apt to be. There is no searching of his understanding; his counsels, by which he governeth all the world, and in a most particular manner thine affairs, are far above the reach of thy understanding; and therefore thou dost ignorantly and foolishly in passing so rash a censure upon the ways and works of the infinitely wise God.