1. Because he would anticipate their boastings of themselves and their idols. (1.) God by his prophets told them beforehand of their deliverance, lest they should attribute the accomplishment of it to their idols. Thus he saw it necessary to secure the glory of it to himself, which otherwise would have been given by some of them to their graven images: "I spoke of it," says God, "lest thou shouldst say, My idol has done it or has commanded it to be done," v. 5. There were those that would be apt to say so, and so would be confirmed in their idolatry by that which was intended to cure them of it. But they would now be for ever precluded from saying this; for, if the idols had done it, the prophets of the idols would have foretold it; but, the prophets of the Lord having foretold it, it was no doubt the power of the Lord that effected it. (2.) God foretold it by his prophets, lest they should assume the foresight of it to themselves. Those that were not so profane as to have ascribed the thing itself to an idol were yet so proud as to have pretended that by their own sagacity they foresaw it, if God had not been beforehand with them and spoken first: Lest thou shouldst say, Behold, I knew them, v. 7. Thus vain men, who would be thought wise, commonly undervalue a thing which is really great and surprising with this suggestion, that it was no more than they expected and they knew it would come to this. To anticipate this, and that this boasting might for ever be excluded, God told them of it before the day, when as yet they dreamed not of it. God has said and done enough to prevent men's boastings of themselves, and that no flesh may glory in his presence, and, if it have not the intended effect, it will aggravate the sin and ruin of the proud; and, sooner, or later, every mouth shall be stopped, and all flesh shall become silent before God.