Paul uses a question for emphasis. The word "Israel" is a metonym for the people who lived in the nation of Israel. Alternate translation: "Again I tell you the people of Israel did know the message." (See: [[rc://en/ta/man/jit/figs-rquestion]] and [[rc://en/ta/man/jit/figs-metonymy]])
This means that Moses wrote down what God said. "I" refers to God, and "you" refers to the Israelites. Alternate translation: "First Moses says that God will provoke you ... God will stir you up" (See: [[rc://en/ta/man/jit/figs-you]] and [[rc://en/ta/man/jit/figs-quotations]])
Here "without understanding" means that the people do not know God. Alternate translation: "By a nation with people who do not know me or my commands" (See: [[rc://en/ta/man/jit/figs-explicit]])