Observance of the Passover

(Book of Numbers 9:1 - 9:14)
Jehovah spoke to Moses in the desert of Sinai in the first month of the second year after their exodus from Egypt.  "Let the Israelites," he told him, "celebrate the Passover at the prescribed time, at dusk on the 14th day of this month, Nisan.  --- And be sure to follow all the rules and regulations I have given you concerning the holiday."

Moses thus told the Israelites that they should celebrate Passover; they did so in the desert of Sinai at dusk on 14th day of Nisan, in accordance with all that Jehovah had commanded Moses.  However, there were a certain number of people who were ritually impure due to their handling of corpses.  They, therefore, did not celebrate Passover on that day, but came to see Aaron and Moses.  They complained to Moses, "We are ritually impure because we have touched dead bodies, but why should that keep us from making offerings to Jehovah at the proper time with the rest of the people of Israel?"

Moses told them, "Wait until I can find out what Jehovah will decree concerning you."

Jehovah answered Moses: "Tell the Israelites that any of them, or their descendants, may still celebrate Passover even if they are ritually unclean due to exposure to a corpse, or if they are away on a journey.  Such persons should observe it at dusk on the 15th day of the second month, Iyar.  They should then eat the Passover lamb with unleavened bread and bitter herbs.  They should break no bone of the lamb nor leave any of its meat by morning.  They must follow all the customs of Passover.  But those who are ritually pure and not away on a journey must observe Passover on the regular day, or else suffer expulsion from the community of Israel, punishment for the sin of failing to present offerings to Jehovah at the proper time.  Any alien residing among you may celebrate Jehovah's Passover, if he chooses to do so, but only according to the established procedures governing its observance. --- There will be a single set of rules and regulations that apply to both natives and foreign-born residents."

Notes
1.  All the rules put out by Jehovah makes everything complicated, even the celebration of holidays.  Moses is not able to figure out how ritually impure folks, those who have handled or been exposed to corpses, can observe Passover.  The decision is above his pay grade, so he must, as he is wont, consult Jehovah, who apparently has the time and inclination to micro-manage every aspect of Israelite society.  One wonders why Jehovah didn't address the ritually impure when he established Passover customs.  Did he not foresee the potential problem?  Or does he enjoy Moses having to run to him with every little thing?

2. Passover was and still is celebrated on 15th day of the Jewish month of Nisan, in March or April.  It extends for seven days.  (The holiday was celebrated for eight days during the Diaspora, the long period of Jewish exile, and is still so observed by many Jews living outside of modern Israel.)  The holiday would begin at dusk on the 14th, as the new day, in Hebrew interpretation, commences at nightfall, not at day break.  It is, therefore, not strictly accurate to refer to the beginning of the holiday as occurring at twilight, as many translations do. (While dusk begins after the sun has set, twilight generally refers to a period before as well as after the setting of the sun.)