Thou hast heard, see all this; and will not ye {g} declare it? I have showed ye new things from this time, even hidden things, and thou didst not know them.

(g) Will you not acknowledge my blessing, and declare it to others?

Wesley's Notes

48:6 See - As thou hast heard all these things, from time to time, seriously consider them. Declare - I call you to witness: must you not be forced to acknowledge the truth of what I say? Shewed - And I have now given thee new predictions of secret things, such as 'till this time were wholly unknown to thee, concerning thy deliverance out of Babylon by Cyrus.

Jamieson-Fausset-Brown Bible Commentary

6. Thou, &c.-So "ye are my witnesses" (Isa 43:10). Thou canst testify the prediction was uttered long before the fulfilment: "see all this," namely, that the event answers to the prophecy.

declare-make the fact known as a proof that Jehovah alone is God (Isa 44:8).

new things-namely, the deliverance from Babylon by Cyrus, new in contradistinction from former predictions that had been fulfilled (Isa 42:9; 43:19). Antitypically, the prophecy has in view the "new things" of the gospel treasury (So 7:13; Mt 13:52; 2Co 5:17; Re 21:5). From this point forward, the prophecies as to Messiah's first and second advents and the restoration of Israel, have a new circumstantial distinctness, such as did not characterize the previous ones, even of Isaiah. Babylon, in this view, answers to the mystical Babylon of Revelation.

hidden-which could not have been guessed by political sagacity (Da 2:22, 29; 1Co 2:9, 10).

Matthew Henry's Concise Commentary

48:1-8 The Jews valued themselves on descent from Jacob, and used the name of Jehovah as their God. They prided themselves respecting Jerusalem and the temple, yet there was no holiness in their lives. If we are not sincere in religion, we do but take the name of the Lord in vain. By prophecy they were shown how God would deal with them, long before it came to pass. God has said and done enough to prevent men's boasting of themselves, which makes the sin and ruin of the proud worse; sooner or later every mouth shall be stopped, and all become silent before Him. We are all born children of disobedience. Where original sin is, actual sin will follow. Does not the conscience of every man witness to the truth of Scripture? May the Lord prove us, and render us doers of the word.