Isaiah 26:14

Render: The dead shall not live, the Shades (Rěphâ" îm, as in Isaiah 14:9) shall not rise, &c. In the form of a general proposition the writer expresses Israel's sense of security with regard to those "other lords" who have now vanished from the earth. The idea is probably suggested by ch. Isaiah 14:9 ff. There is no contradiction between this verse and Isaiah 26:19, nor is there any evidence of a merely nascent belief in the possibility of a resurrection; because the subjects in the two verses are different. The resurrection of Isaiah 26:19 is distinctly represented as miraculous, and is limited to members of the covenant people; over those who are unvisited by the life-giving "dew" of Jehovah, the sway of death is absolute.

therefore i.e. in token that they shall never reappear, all traces of their supremacy have been obliterated.

all their memory every memorial of them.