en_tn_condensed/isa/40/28.md

Have you not known? Have you not heard?

Isaiah uses these questions to emphasize that the people should know Yahweh's greatness. See how you translated these in Isaiah 40:21. AT: "You certainly know and have heard!" (See: rc://en/ta/man/translate/figs-rquestion)

the ends of the earth

The places on the earth that are very far away are spoken of as if they were the places where the earth ends. This phrase also forms a merism and refers to everywhere in between the ends. AT "the farthest places of the earth" or "the entire earth" (See: rc://en/ta/man/translate/figs-metaphor and rc://en/ta/man/translate/figs-merism)