וַיְהִ֤י כַחוֹל֙ זַרְעֶ֔ךָ וְצֶאֱצָאֵ֥י מֵעֶ֖יךָ כִּמְעֹתָ֑יו לֹֽא־יִכָּרֵ֧ת וְֽלֹא־יִשָּׁמֵ֛ד שְׁמ֖וֹ מִלְּפָנָֽי׃
Thy seed also would be as the sand, And the offspring of thy body like the grains thereof; His name would not be cut off Nor destroyed from before Me.
Read midrashic interpretation of Isaiah 48:19: and classical rabbinic exegesis.