Jeremiah uses a question to scold the people. Alternate translation: "Yahweh certainly knew about ... of the land." (See: [[rc://en/ta/man/translate/figs-rquestion]])
Both of these phrases mean the same thing. They emphasize that Yahweh knows that the people were worshiping false gods. Alternate translation: "Yes, Yahweh knows what you were doing, and he does not forget" (See: [[rc://en/ta/man/translate/figs-parallelism]])