en_tn_condensed/isa/63/16.md

though Abraham does not know us, and Israel does not recognize us

These ancestors of the nation of Israel would not able to identify their descendants because they changed so much. "Abraham" and "Israel" represent the people from the distant past. (See: rc://en/ta/man/translate/figs-synecdoche)

Israel

This refers to the name also called "Jacob."