Isaiah 63:5

5.I looked, and there was none to help. Although the Jews were destitute of all assistance, and no one aided them by word or deed, yet he shews that the arm of the Lord is alone sufficient to punish enemies, and to set his people at liberty. He shews, therefore, that from God alone they ought to expect salvation, that they may not gaze around in every direction, but may have their eyes wholly fixed on God, who has no need of the assistance of others.

And I wondered. He represents God as amazed that there is none to stretch out a hand to him, when he wishes to execute his judgments, that he may impress more deeply on the minds of believers this doctrine, that God has no need of human aid, and that he is sufficient of himself for procuring salvation to his people. By this circumstance he magnifies still more the assistance which he had determined to render to his people, partly to correct their distrust, and partly to exhort them to gratitude in future; for God assumes a different character, when he says that he stood like one astonished; because this stupidity belonged literally to the Jews, who scarcely believed what could not be done by the power of men. With every assistance, therefore, he contrasts his own arm, with the invincible power of which he says that he will be satisfied, both that he may be seen to be their Savior, and that he may scatter and lay low all the wicked.