Num 9:1-13 And the LORD spoke to Moses in the wilderness of Sinai, in the first month of the second year after they had come out of the land of Egypt, saying, “Let the people of Israel keep the Passover at its appointed time. On the fourteenth day of this month, at twilight, you shall keep it at its appointed time; according to all its statutes and all its rules you shall keep it.” So Moses told the people of Israel that they should keep the Passover. And they kept the Passover in the first month, on the fourteenth day of the month, at twilight, in the wilderness of Sinai; according to all that the LORD commanded Moses, so the people of Israel did. And there were certain men who were unclean through touching a dead body, so that they could not keep the Passover on that day, and they came before Moses and Aaron on that day. And those men said to him, “We are unclean through touching a dead body. Why are we kept from bringing the LORD’s offering at its appointed time among the people of Israel?” And Moses said to them, “Wait, that I may hear what the LORD will command concerning you.” The LORD spoke to Moses, saying, “Speak to the people of Israel, saying, If any one of you or of your descendants is unclean through touching a dead body, or is on a long journey, he shall still keep the Passover to the LORD. In the second month on the fourteenth day at twilight they shall keep it. They shall eat it with unleavened bread and bitter herbs. They shall leave none of it until the morning, nor break any of its bones; according to all the statute for the Passover they shall keep it. But if anyone who is clean and is not on a journey fails to keep the Passover, that person shall be cut off from his people because he did not bring the LORD’s offering at its appointed time; that man shall bear his sin.
It was not a surprise for Israel to hear that Passover must be kept every year. When Passover was first instituted, God told Israel they were to keep it throughout their generations. “The long stay at the base of Mount Sinai was not a time of inactivity or indolence. It was a time of great activity in celebration of the goodness and mercy of the Lord and in preparation for what was expected to have been the soon triumphal march into the land of Canaan.” The blood of the lamb, applied to the door posts of the home, was seen by the angel of God’s judgment – and seeing the blood, the angel “passed over” and spared the home covered by the blood of a lamb. Passover was kept as a continual reminder of this occasion of judgment passed over, and of the deliverance from slavery that followed. Jesus fulfilled the Passover sacrifice by His death on the cross (1 Corinthians 5:7). The covering of His blood causes the judgment of God to “pass over” His people. We are commanded to continually remember our occasion of being spared judgment and the deliverance that followed, by remembering Jesus’ work on the cross through the Lord’s Supper. Israel was properly obedient to God. We don’t find any significant disobedience against God of distrust of Him on Israel’s part in the first 10 chapters of Numbers, while they camped at Mount Sinai. This makes their distrust of God and rebellion against Him even more shocking and without excuse from Numbers 11 on. (Guzik)
But lest any one should pervert this permission, to celebrate the Passover a month later in case of insuperable difficulties, which had only been given for the purpose of enforcing the obligation to keep the covenant meal upon every member of the nation, into an excuse for postponing it without any necessity and merely from indifference, on the ground that he could make it up afterwards, the threat is held out in Numbers 9:13, that whoever should omit to keep the feast at the legal time, if he was neither unclean nor upon a journey, should be cut off. (Keil)
Remembering how God, in the time of judgment, passed over the Israelites is no small thing. God’s judgment was announced and carried out. There was no waiting, no stopping, or turning away from it so that it did not affect those it was intended for. Remembering God in His deliverance, mercy, and grace being saved from the slavery of sin and judgment is upon all who believe. It is no small thing that God has done. It should always be in the front of our minds. He deserves all honor and glory and praise, for He has done great and wonderful things.