The question emphasizes that they should not say what they say. Alternate translation: "'You should not say, O people of Israel ... vindication'." (See: [[rc://en/ta/man/translate/figs-rquestion]])
These two phrases both refer to the people of Israel. Alternate translation: "Why do you say, O people of Israel" (See: [[rc://en/ta/man/translate/figs-doublet]])
Yahweh not knowing what happens to them is spoken of as if Yahweh could not see the road upon which they travel. Alternate translation: "Yahweh does not know what happens to me" (See: [[rc://en/ta/man/translate/figs-metaphor]])