What exactly is Moshe's telling the people here?
Rashi #1: He is warning them that, now that they have matured and have come to grips with Hashem and His Torah, they should not allow their high standing and great achievements to go to their heads, because from on, Hashem will no longer turn a blind eye to their sins, but will take them to task and punish them if they go astray. 1
Rashi #2: Refer to 29:9:3:2**.
Seforno (Pesukim 4-6): Now that they had witnessed Hashem's kindnesses that He performed with them in the desert so that they should learn from them, and that He has brought them to the land of Sichon and Og, to give them an inheritance of their own, where they are able to achieve what He intended them to, it behoves them well to set their minds to know from now on. And finally, if they will adhere to the covenant that they will enter into at Har Gerizim and Har Eival, then they will succeed in all their endeavors, as regards both this world and the world to come.
