Parshas Re’eh
“You may not sacrifice the Passover offering in one of your gates that Hashem your G-d gives you” (Devarim 17,5)
It is a negative commandment not to sacrifice the Passover lamb on a private altar even in an era where private altars where permitted. In that time each and every individual in Israel who desired to offer up a sacrifice would build a building in any place he wanted and sacrifice his offerings to Hashem may He be blessed, there. This era was before the building of the Beis Hamikdash. Even in that era, this authorisation was only given to other sacrifices but the sacrifice of Passover was only ever offered at a public altar and that was the place where the Mishkan was situated. About this it says “You may not sacrifice the Passover offering in one of your gates that Hashem your G-d gives you”.
Amongst the roots of the commandment: To affix in our souls the magnitude of the subject of Passover and the value of the commandment for the reason which I have written about a number of times. In truth, the honor of the commandment and the publicity of it will be greater when everybody together performs it in one specific place rather than each individual doing it in the place which he desires.
This prohibition applies at a time when the Beis Hamikdash is standing, for then we can sacrifice the Passover offering, it applies to men and to women. One could say, that even nowadays, one who transgresses and sanctifies a lamb for Passover and offers it up on a private altar, has transgressed this prohibition and is penalized with lashes. (malkus)
