The Lord's Reminding the People of Idolatry

In the middle section of deuteronomy, chapter four, between verses nine and 24? Where does where does the lord go through moses for motivation? Well at this point, yet again, moses is trying to motivate the people to obedience. And so he reminds them of the original giving of the law at sinai in verse 13. He's showing that the lord can't be represented by or imaged by any of these things.