This rhetorical question continues the idea that the people of Israel think Yahweh's commands are too difficult to know. This question can be translated as a statement. AT: "Someone must travel across the sea to learn God's commands and then return and tell us what they are." (See: [[rc://en/ta/man/translate/figs-rquestion]])
# in your mouth and your heart
This means that the people already know God's commands and can tell them to others. (See: [[rc://en/ta/man/translate/figs-metonymy]])