2,507. Claiming Disqualifying Intentions Just to Aggravate Someone

Hilchos Shechita 2:20

If a woman slaughters an animal for the burnt offering brought after giving birth, saying that it’s for her burnt offering, her slaughtering is valid because the burnt offering of a woman who has given birth can’t be brought about with a vow or a pledge; since this woman hasn’t given birth, she simply isn’t obligated in the burnt offering. We aren’t concerned with the possibility that she might have miscarried (and is therefore obligated in the offering) because if such were the case, it would become known. Conversely, if someone slaughters for the burnt offering of a nazir (nazarite), the slaughter is invalid even if he’s not a nazir because the main point of being a nazir is a vow (which might be kept private).

Hilchos Shechita 2:21

Let’s say that two people hold a knife and slaughter an animal together. One of them has a disqualifying intention in mind and the other has no intention, or a permitted intention. In such a case, the slaughter is invalid. Similarly, if they slaughtered in immediate succession and one of them has a disqualifying intention, it is invalid. This is the case when the one with the disqualifying intention owns part of the animal; if he doesn’t own part of the animal, it isn’t rendered prohibited. This is because Jews don’t render other people’s property prohibited and he’s only saying that he has disqualifying intentions in order to give the other person grief.