This is the climax of Israel's sin. All else in this history is judgment, until Israel is removed from the Land and taken away out of God's sight. His name is practically blotted out, never again to be a separate ten-tribed kingdom. So blotted out, in fact, that men speak today of the lost  ten tribes.
Indeed, the prophecy of Deut. xxix.20 is fulfilled, not only as to the individual and to the Tribe; but there is an application to the whole nation. In Deut. xxix.18, 20 (17, 19) there is the threat to blot out the name of the "man" or "tribe" who shall introduce idolatry. As a matter of fact, the Tribes of Dan and Ephraim were the first to introduce it; and their names are blotted out from the tribes of those who are to be sealed in Rev. vii.
It is in this Epistle, next in order (to the assembly at Sardis) that we have the reference to this silence, in the promise to the few names of such as have not defiled their garments: "He that overcometh... I will not blot out his name out of the book of life, but I will confess his name before my Father and before his Angels" (Rev. iii.5).
 Not that they are "lost" in the proper sense of the word: but the proverbial expression is significant.