v1: The Feast of Passover was central to the annual round of Feasts. As well as being the first feast, it was to remember their deliverance from Egypt.
The deliverance from Egypt is presented as a reason for obedience in many areas; how to treat false prophets (13.5,10), how to treat slaves (15.15), why not to fear powerful nations (20.1), why justice must be upheld (24.18), and treating others with kindness (24.22). In a similar way, the death of Christ must affect how the Christian lives his life.
v2-4: The sacrifice of passover and the unleavened bread. The original event was annually re-enacted, so that the people might remember what God had done for them. The command here is that throughout their lives, the people might remember the deliverance from Egypt.
v5-6: The Passover had to be celebrated at the place of God's choosing.
v7-8: Brief details of the feast to be celebrated; it was to be where the Lord God chose, which was ultimately Jerusalem; there were to be six days of eating unleavened bread, and the seventh day was the Passover, an 'extra Sabbath,' when no work would be done, and the people would gather to worship God.
It is not surprising that this feast became the precursor for the Lord's Supper, when Christians meet to share bread and wine, and remember the death of the Lord Jesus. Amongst other things, this is a means by which the wonderful salvation wrought by Christ is kept in our minds.
v9-12: The feast of Weeks, or Pentecost, was a Feast of thanksgiving, of the Lord God's provision for His people, and again of the deliverance from Egypt.
v13-15: In the Feast of Tabernacles, at the end of their year, the people continued to be grateful for all that God had given.
v16-17: These three feasts were to be celebrated as a nation, and in the place chosen by God.
No one could come empty handed, since the Feasts were a sign of God's blessing; no one could be empty handed.
v18-20: Judges were to be appointed; leadership was delegated, and had to be just.
v21-22 Verses belonging to the following section; avoid idolatry, in any and every form.