NOTES for Num 9:1-23
Judging by the prescriptions contained in the book of Numbers, the Yahwism of the Mosaic era was very far from that religious formalism which over time, unfortunately, became almost an inseparable part of it. Of course, formalism was never its defining component - otherwise its history could have ended even before the coming of Christ - yet often it was very noticeable both in Yahwism and in the Judaism that grew from it.
So it is with all religiosity: it inevitably strives for the primacy of form over content simply because, in itself, it is essentially form. The true content of any religious tradition is not religiosity as such, but the revelation it contains, often hiding it in a religious shell like a kind of case. In the era of Moses, what predominated was not religious formalism, but the revelation thanks to which Yahwism became what it became.
The prescriptions for celebrating Passover are clear evidence of this. It would seem easiest simply to forbid participation in the feast to those who had not managed to prepare. But God's revelation is unambiguous: everyone may participate, even if, for those who did not manage to prepare, the celebration is moved by one day. Participation in the feast, which presupposes the sanctification of the people, turns out to be more important than the calendar: if a person does not make it by the appointed time and the delay is not too great, let him join as soon as he is ready.
Even if the people were given detailed rules of ritual purity, in those days they were truly necessary: death then was all-powerful, and defilement was one of its manifestations, so one had to flee defilement as from fire. Otherwise it would not have been possible to follow God step by step, as the same book of Numbers prescribes: when the cloud of God's presence moved, the people moved; when it stayed in place, the people stood and did not set out. It was necessary constantly to see this shining cloud and not lose sight of it - and a defiled person could easily stop noticing it. In that case the people would have been left with only the wilderness - a wilderness not only without food and water, but also without God.