Moses was their king, not in title, but in reality, being under God their supreme and uncontrollable governor and lawgiver: though the word oft signifies only a prince or chief ruler, as Judges 19:1 Jeremiah 19:3, Jeremiah 46:25. In Jeshurun, i.e. in Israel, so called Deuteronomy 32:15. When the heads of the people and the tribes of Israel were gathered together: when the princes and people met together for the management of public affairs, Moses was owned by them as their king and lawgiver, and he directed and ruled them as their superior. This he saith to show that the people approved and consented to the authority and law of Moses.
Related Commentaries of Deuteronomy 33:5
Deuteronomy 33:5
5 And he was king in Jeshurun, when the heads of the people and the tribes of Israel were gathered together.