Isaiah 45:15

Verily thou art a God that hideth thyself
Who hid himself from the Gentile world for some hundreds of years, who had no knowledge of the true God, lived without him in the world, and whose times of ignorance God overlooked, and suffered them to walk in their own ways; though now he would make himself known by his Gospel sent among them, and blessed for the conversion of them. He is also a God that hides himself from his own people at times, withdraws his gracious presence, and withholds the communication of his love and grace. These seem to be the words of the prophet, speaking his own experience, and that of other saints: or rather of the church, upon the access of the Gentiles to her, declaring what the Lord had been to them in former times; but now had showed himself to them in a way of grace and mercy. Some render it "thou art the hidden God" ^F26; invisible in his nature; incomprehensible in his essence; not to be found out to perfection, nor to be traced in his providential dispensations; his judgments are unsearchable, and his ways past finding out. It may be applied to Christ in his state of humiliation; for though he was God manifest in the flesh, yet the glory of his deity was seen but by a few, being hid in the coarse veil of humanity; he appearing in the form of a servant, who was in the form of God, and equal to him; and to him the following words agree: O God of Israel, the Saviour;
for he is God over all, and the God of his spiritual Israel in an especial manner; and the Saviour of them from sin, wrath, condemnation, and death, by his obedience, sufferings, and death; or if it is to be understood of God the Father, who is the God of Israel, he is the Saviour of them by his Son.