v1: This chapter introduces a new section, to ch 26, where the standards of God are clearly laid down. "These are the decrees and laws..."; this is what the Holy God expects of His people.
v2-3: All evidence of idolatry had to be destroyed. Even the objects of idolatry were not to be used in the worship of God. The people were not even to ask, "How do these nations serve their gods?" (v30). For the Christian, such things as legalism, fatalism, mysticism, pragmatism, and many more, corrupt true doctrine and worship.
v4: The way of worship of a false god was also false. We cannot use false means to worship the true God.
v5-7: A specific place of worship was to be set apart (see John 4.20). This was important, as it introduced a clear standard to be observed, rather then multiplying places, and therefore styles and content. In Jer 11.13 the people had reverted to multiple places of worship, and that had not promoted holy living.
The single place of worship was to be a place of rejoicing, as in v12. The people would look forward to going to Jerusalem (Ps 122.1).
For the Christian, worship is in Jesus Christ, and only in Him.
v8: The specific danger, that each one did what was right in their own eyes, instead of submitting to the word of God. The people returned to this in Judg 21.21. Moses' words here suggest that the people had already begun to please themselves.
v9: Once in Canaan, the people were expected to put away their own ways of life, and submit to God's standards. This is consistent with Moses' repeated references to obedience in Canaan; 6.1-3, for example.
v10: Canaan was the place of rest; this was fulfilled in 1 Chr 22.18, centuries later, through the reign of King David. The true rest is in Christ (Heb 3.8-10).
v11: The place chosen by God was for the people to bring their burnt offerings and gifts.
v12: The whole people would come together at Jerusalem to rejoice before the Lord.
v13-14: Their offerings were not to be made anywhere the people wanted. When they departed from this command, they quickly fell into idolatry.
The place set apart by God was to become the focus for the religious life of the nation, and would also promote unity. See 1 Kings 12.26-27, where Jeroboam built alternative places of worship to prevent the people from re-uniting.
v15-18: To clarify matters, Moses explained that the people could kill and eat their ordinary food at home. But any offerings to the Lord had to be made at the chosen place, in the presence of God. Part of this was so that the Levites would receive food, for they were provided from the offerings of the people. This is why the command on v19 is mentioned.
v20-25: When the land occupied by Israel grew, such that the journey to Jerusalem became too long, the Lord allowed the people to kill and eat at home. But still the tithes and gifts are not mentioned; the people still had to come together to offer to God.
v26: The people had to take the consecrated things to the chosen place.
v27-28: The way the offerings were to be made was laid down, just as the place was. Again, we see that worship of God had to be done God's way. There was a real blessing in obedience here.
v29-31: The nations of the land were to be cast out. It was important that Israel did not learn from them. Corrupt worship led to corrupt practices.
v32: The danger of adding or subtracting from God's word. God presented to Israel something complete and wonderful. They were not to change what He had said.