Moses reminded the Israelites of God's great mercy to them, notwithstanding their provocations. There were four things in and by which the Lord showed himself reconciled to Israel. God gave them his law.
Thus God has intrusted us with Bibles, sabbaths, and sacraments, as tokens of his presence and favour. God led them forward toward Canaan. He appointed a standing ministry among them for holy things.
And now, under the gospel, when the pouring forth of the Spirit is more plentiful and powerful, the succession is kept up by the Spirit's work on men's hearts, qualifying and making some willing for that work in every age.
God accepted Moses as an advocate or intercessor for them, and therefore appointed him to be their prince and leader. Moses was a type of Christ, who ever lives, pleading for us, and has all power in heaven and in earth.