Treasury of Scripture Knowledge

Summary

But the man that is clean, and is not in a journey, and forbeareth to keep the passover, even the same soul shall be cut off from among his people: because he brought not the offering of the LORD in his appointed season, that man shall bear his sin.

Because

Bible References

Forbeareth

Numbers 15:30
But the one {who acts presumptuously} from among the native or alien blasphemes against Yahweh, and that person must be cut off from the midst of the people.
Numbers 19:13
Anyone who touches a corpse, the person of a human being who died, and does not purify himself, defiles the tabernacle of Yahweh, and that person will be cut off from Israel because the waters of impurity were not sprinkled on him. He will still be unclean, and uncleanness [is] on him.
Genesis 17:14
And [as for any] uncircumcised male who has not circumcised the flesh of his foreskin, that person shall be cut off from his people. He has broken my covenant.
Exodus 12:15
You will eat unleavened bread for seven days. Surely on the first day you shall remove yeast from your houses, because anyone [who] eats [food with] yeast from the first day until the seventh day--that person will be cut off from Israel.
Leviticus 17:4
and he does not bring it to the tent of assembly's entrance to present an offering to Yahweh {before} Yahweh's tabernacle, then that man shall be accounted bloodguilty--he has poured out blood, and that man shall be cut off from the midst of his people.
Hebrews 2:3
how will we escape [if we] neglect so great a salvation which had [its] beginning [when it] was spoken through the Lord [and] was confirmed to us by those who heard,
Hebrews 6:6
and having fallen away, to renew [them] again to repentance, [because they] have crucified again for themselves the Son of God and held him up to contempt.
Hebrews 10:26
For [if] we keep on sinning deliberately after receiving the knowledge of the truth, there no longer remains a sacrifice for sins,
Hebrews 12:25
Watch out that you do not refuse the one who is speaking! For if those did not escape [when they] refused the one who warned [them] on earth, much less [will] we [escape], [if we] reject the [one who warns] from heaven,

Because

Numbers 9:2
"Let the {Israelites} observe the Passover at its appointed time.