לזכות אלחנן בן הענא מרים לפרנסה ובריאות!!
Continuing from here... [I thank my beloved chavrusa, R' Simcha Yusopov, with whom I learned this sugya and many others - for teaching me Zevachim]
HaGaon Rav Isser Zalman Meltzer ztz"l explains that since one is not yotzei [אינו מרצה] with a Pesach that was shechted for the sake of another animal, it emerges that he has to become registered [מנוי] on Pesach Sheni. Since one can't be registered on two Pesachim, hee is only allowed to eat from the second Pesach and the first Pesach has been shechted for an unregistered person rendering it pasul. So regarding Korban pesach there is no מציאות of כשר ואינו מרצה [See Even Ha-ezel at length].
This is difficult because the implication of the Rambam is that there is a problem with the machshava itself that it is considered לא לשמה and not just that because of his machshava the korban will not be מרצה requiring him to register on Pesach Sheni etc. where the machshava itself is not a problem - only the consequence of the machshava. Another problem is that the Rambam paskens that a Korban Pesach can be כשר ואינו מרצה.
The Minchas Chinuch cites an answer he heard that the pasuk ואמרתם זבח פסח from which we learn the psul of פסח שלא לשמו was stated about פסח מצרים and at that time there were no other korbanos, so it must be referring to the psul of a פסח לשם חולין. The MC isn't thrilled with this answer because it says at the beginning of that section והיה כי תבואו אל הארץ וכו' ואמרתם זבח פסח הוא - doesn't sound like פסח מצרים to me..... [Although there is a Mechilta that bears out this terutz].
|HaGaon Rav Berel Povarsky Shlita|
HaGaon Rav Berel Povarsky Shlita, one of the leading Roshei Yeshiva on the Planet Earth [and all planets for that matter - I once was zoche to use an esrog he chose for the whole Succos. It was by far the most beautiful and expensive esrog I have ever used. It's a whole story how I got it...] gives a lengthy answer which can be summarized by saying that besides the regular "din korban" of a Pesach there is a special "din Pesach". With regard to this "din Pesach" we require a מחשבה לשם פסח and thus any מחשבה לשם חולין will disqualify.
He was SOOOOOO kind to write his answer out for us at Mevakesh and I present it here.
Please read and understand:-).