And he said, Behold, I make a covenant: before all thy people I will do marvels, such as have not been done in all the earth, nor in any nation: and all the people among which thou art shall see the work of the LORD: for it is a terrible thing that I will do with thee. I will do marvels - This seems to refer to what God did in putting them in possession of the land of Canaan, causing the walls of Jericho to fall down; making the sun and moon to stand still, etc. And thus God made his covenant with them; binding himself to put them in possession of the promised land, and binding them to observe the precepts laid down in the following verses, from Exodus 34:11-26 inclusive.
Related Commentaries of Exodus 34:10
Exodus 34:10
10 And he said, Behold, I make a covenant: before all thy people I will do marvels, such as have not been done in all the earth, nor in any nation: and all the people among which thou art shall see the work of the LORD: for it is a terrible thing that I will do with thee.