(Bamidbar 9:2) "And the children of Israel shall offer the Pesach in its appointed time": Why is this stated? (i.e., Isn't it obvious?) From (Shemot 12:6) "and the whole congregation of Israel shall slaughter it (the Paschal lamb)," I might think, either on a weekday or on Sabbath (as the case may be). And how would I satisfy (Ibid. 31:14) "Its (Sabbath's) desecrators shall be put to death"? With other labors, other than slaughtering the Paschal lamb. — Or, even with slaughtering the Paschal lamb.
And how would I satisfy "and they shall slaughter it"? (If it falls out) on other days, other than Sabbath. It is, therefore, written "And the children of Israel shall offer the Pesach in its appointed time" (— even on the Sabbath). These are the words of R. Yoshiyah. R. Yonathan (to R. Yoshiyah): This is not sufficient (for the derivation [i.e., "in its appointed time" may mean if it does not fall out on a Sabbath.])
R. Yoshiyah (to R. Yonathan): Rather, it is written (Bamidbar 28:2) "Command the children of Israel and say to them … to offer (the tamid) offering to Me in its appointed time." If (the intent of this is) to teach that the tamid offering overrides Sabbath, this is not needed; for it is already written (Ibid. 9) "And on the Sabbath day, (there are to be sacrificed) two lambs of the first year … (10) the burnt-offering of the Sabbath in its Sabbath in addition to the daily burnt-offering, etc." What, then, is the intent (of "in its appointed time")?
It is "extra," to signal the formulation of an identity, viz.: it is written here "in its appointed time," and elsewhere (re the Paschal lamb) "in its appointed time." Just as "its appointed time" here overrides Sabbath, so, "its appointed time" there overrides Sabbath. "On the fourteenth day of this month, towards evening shall you offer it, in its appointed time.": What is the intent of this? Is it not already written "The children of Israel shall offer it in its appointed time"?
Why, again, "in its appointed time"? Scripture hereby comes to teach us that just as the first Pesach (as opposed to Pesach Sheni) overrides the Sabbath, so it overrides (communal) uncleanliness. For (without this verse,) it would follow otherwise, viz.: If (the slaughtering of) the red heifer, which does not override the Sabbath overrides (communal) uncleanliness, the first Pesach, which overrides the Sabbath, how much more so should it override uncleanliness? — This is refuted by the second Pesach, which even though it overrides the Sabbath, does not override uncleanliness.
And this would indicate of the first Pesach that even though it overrides the Sabbath, it does not override uncleanliness. It is, therefore, written "in its appointed time," to teach concerning the first Pesach that just as it overrides the Sabbath it overrides uncleanliness. (Bamidbar, Ibid.) "According to all of its statutes": These are the mitzvoth (directly) pertaining to its body, viz. (Shemot 12:5) "an unblemished lamb, a male, of the first year." "its ordinances": These are the mitzvoth attendant upon its body, viz. (Devarim 16:3) "Seven days shall you eat matzoth 'upon' it." "according to all its ordinances": to include mitzvoth not attendant upon its body — the eating of matzoh for seven days and the burning of chametz.