Va'etchanan - Rishon
The Mitzvos, More or Less
Since God had not permitted Moshe to enter the Holy Land, he decided to pray to God for a pardon. God told Moshe to stop. As a consolation prize, God told Moshe to climb to a certain mountain peak from where He would show him the land.
Now Moshe begins a review of the mitzvos (commandments) for the benefit of the younger generation, who are about to cross over into Israel. These are the mitzvos, which we may not alter by adding to or subtracting from them. (This doesn't mean that Rabbinic laws could not be enacted; the leaders were actually commanded to institute such laws as safeguards to protect the mitzvos from being violated. Not adding or subtracting means things like not waving three or five species on Succos rather than four, not having two or four priestly blessings rather than three, etc. See Rashi on 4:2.) The people saw how God destroyed those who had worshipped the idol Baal Peor (in parshas Balak, Numbers chapter 25). The result was that those remaining were good, God-fearing individuals. (Verse 4, "And all of you who cling to your God remain alive today," is recited when we call the kohein up for the first aliyah of a Torah reading.)