The people used this question to accuse Moses. It can be translated as a statement. Alternate translation: "Now you want to blind us with empty promises." (See: [[rc://en/ta/man/translate/figs-rquestion]])
They speak of promises that are not kept as if they are empty containers. Alternate translation: "with promises that you do not keep" or "by promising to do things that you do not do" (See: [[rc://en/ta/man/translate/figs-metaphor]])