Sefer HaChinuch ספר החינוך

That we not feed of the Pesach sacrifice to an apostate Jew: That we not feed of (allow to eat from) the Pesach sacrifice to a Jew that is a habitual sinner of idolatry, as it is stated (Exodus 12:43), “no foreigner shall eat of it.” And the understanding (Mekhilta DeRabbi Shimon Bar Yochai 12:43) comes upon it that [this “foreigner”] is a Jew whose actions have become foreign to his Father in Heaven. And so did Onkelos translate.

From the roots of this commandment is like that which is written about its slaughter (Sefer HaChinukh 5) — that it is to remember the miracles of Egypt. And therefore it is fitting that a habitual sinner (apostate) not eat from it. Since we are doing it as a sign and as a memory device that we came at that time to take refuge under the wings of the Divine Presence and that we entered into the covenant of Torah and faith, it is not fitting that we feed him — someone who is the opposite of this and went out from the group and denied the faith — of it. And sometimes it is said in the Gemara about things similar to this, “It is logical” — meaning to say that there is no need for a [further] proof (Mishneh Torah, Laws of Paschal Offering 9).

And [it] is practiced by males and females at the time of the [Temple], where there is a Pesach sacrifice. And the one who transgresses it and feeds a “foreigner” from it violates this negative commandment. And there are no lashes for it, since there is no act [involved] with it (Mishneh Torah, Laws of Paschal Offering 9:7).