Isaiah 45:15

“Verily thou art a God that hideth thyself, &c.] 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…”

“God that hidest thyself--HORSLEY, after JEROME, explains this as the confession of Egypt, &c., that God is concealed in human form in the person of Jesus. Rather, connected with Isa 45:9-10, the prophet, contemplating the wonderful issue of the seemingly dark counsels of God, implies a censure on those who presume to question God's dealings (Isa 55:8-9; Deu 29:29). Faith still discerns, even under the veil, the covenant-keeping "God of Israel, the Saviour" (Isa 8:17).”

“Verily thou art a God that hidest thyself - That is, that hidest thy counsels and plans. The idea is, that the ways of God seems to be dark until the distant event discloses his purpose; that a long series of mysterious events seem to succeed each other, trying to the faith of his people, and where the reason of his doings cannot be seen. The remark here seems to be made by the prophet, in view of the fact, that the dealings of God with his people in their long and painful exile would be to them inscrutable, but that a future glorious manifestation would disclose the nature of his designs, and make his purposes known (see Isaiah 55:8-9): ‘My thoughts are not your thoughts, neither are your…”

“Verily - These are the words of the prophet, on contemplation of the various dispensations of God towards his church, and in the world. Hidest - Thy counsels are deep and incomprehensible, thy ways are past finding out. Isaiah 45:19”

“a God: Isa 8:17, Isa 57:17; Psa 44:24, Psa 77:19; Joh 13:7; Rom 11:33, Rom 11:34 O God: Isa 45:17, Isa 12:2, Isa 43:3, Isa 43:11, Isa 46:13, Isa 60:16; Psa 68:26; Mat 1:22, Mat 1:23; Joh 4:22, Joh 4:42; Act 5:31, Act 13:23; Pe2 3:18 Isaiah 45:16”

“What follows in Isa 45:15 is not a continuation of the words of the Gentiles, but a response of the church to their confession. The nations that have been idolatrous till now, bend in humble spontaneous worship before the church and its God; and at the sight of this, the church, from whose soul the prophet is speaking, bursts out into an exclamation of reverential amazement. "Verily Thou art a mysterious God, Thou God of Israel, Thou Savour." Literally, a God who hides Himself (mistattēr: the resemblance to μυστηρ-ιώδης is quite an accidental one; the ē is retained in the participle even in pause). The meaning is, a God who guides with marvellous strangeness the history of the nations of…”