Exodus 12:43  And the LORD said unto Moses and Aaron, This is the ordinance of the passover: There shall no stranger eat thereof:
44  But every man’s servant that is bought for money, when thou hast circumcised him, then shall he eat thereof.
45  A foreigner and an hired servant shall not eat thereof.
46  In one house shall it be eaten; thou shalt not carry forth ought of the flesh abroad out of the house; neither shall ye break a bone thereof.
47  All the congregation of Israel shall keep it.
48  And when a stranger shall sojourn with thee, and will keep the passover to the LORD, let all his males be circumcised, and then let him come near and keep it; and he shall be as one that is born in the land: for no uncircumcised person shall eat thereof.
49  One law shall be to him that is homeborn, and unto the stranger that sojourneth among you.
50  Thus did all the children of Israel; as the LORD commanded Moses and Aaron, so did they.
51  And it came to pass the selfsame day, that the LORD did bring the children of Israel out of the land of Egypt by their armies.

The Passover was an important feast for the nation of Israel. You will notice that it is called an “ordinance”. It is not called a “sacrament”. The Catholics have a number of sacraments that they claim are necessary to their imagined salvation. They promote works as the means of their false salvation.
An ordinance is a command to observe some particular event. An ordinance does not have any saving merit. It is important to observe as a reminder, but it does not save. The Hebrews were spared the death of their firstborn by trusting in the LORD’s command. They obviously proved that trust by doing what they were told to do. The faith was required in order to make the actions worthy. We see that in verse 43. No stranger was to eat of the passover. It was for those who met a certain criteria. In verse 44 we see that the man servant that was bought for money and circumcised, could partake of the passover. Circumcision was not a forced event. It was something the stranger would need to agree to. The stranger would need to want to identify with the Hebrew people.
In verse 45 we are again reminded that a foreigner or a hired servant was not allowed to eat of the passover. The person partaking needed to be submissive to the law of God. They needed to see the value of submitting to that law. It required faith in the legitimacy and validity of the law. In this case it was the law of the Passover. The Passover was a one time event where the firstborn was spared by believing the LORD’s command and doing it. After that the Passover was a remembrance of that one time event. God did not threaten to kill the firstborn if the people did not observe the remembrance of the passover. He did warn that the person who did not want to keep the ordinance was to be cut off from the nation of Israel.
in this and many other accounts, we are reminded of what God directed James to write:

James 2:20  But wilt thou know, O vain man, that faith without works is dead?

In verse 46 we read that there was an order as to how the passover was to be remembered. It was to be eaten in one house. They were not to travel from house to house to partake of this remembrance. The meat was not to be carried outside of the local house. There was also not to be any bone of the lamb broken. This was very important. No bone of the Lord Jesus Christ was broken in His crucifixion. Even as the soldiers nailed Jesus to that cross, God directed the placement of the nails in such a way that no bone was broken. The soldiers would not have cared about that detail, but the LORD certainly cared.
We see in verse 47 that this was an ordinance for the entire nation of Israel to observe. In verse 48 we are again reminded that the stranger needed to first of all be circumcised before he could partake of this feast. No uncircumcised male was to be allowed to partake of this meal. The Muslims have a form of what they call female circumcision. What they are doing there is abusive. It is not commanded by the LORD. The LORD instituted circumcision in the days of Abraham and it was for the males in Israel.
The original passover was specific to the nation of Israel. It was instituted by the LORD as the means by which the firstborn of the nation of Israel would be spared death on a particular night. The remembrance of that event was for the nation of Israel and anyone who would want to submit to the requirement for becoming a part of that nation.
This was a picture of the fact that the Lord’s Supper, which is the anti-type of the Passover, is for those who are born again. Lost people gain nothing from partaking of the Lord’s Supper. In fact the Lord warns that those who partake of the Lord’s Supper unworthily bring His condemnation upon themselves.
We see in verse 49 that there was one law for partaking of this memorial. It did not matter if the person was born a Jew or became a Jew through submission to the law and the males being circumcised. Faith in the truth was essential to being accepted in the Hebrew family.
In verse 50 we read that the children of Israel did as the LORD had commanded them. Biblical obedience is not something that can be forced upon a person. It is something that is done in submission to the will of God.
In verse 51 we read that there was no hesitation in obeying the LORD’s command. The LORD brought the children of Israel out of Egypt on a particular day. They had obeyed and eaten the passover on that day. They were delivered from the clutches of the Egyptians. Once again God referred to the children of Israel as armies. They were the disciplined army of God. He did the fighting. They needed to follow His lead obediently.
Pastor Bartel