Tonight is the yahrtzeit of the holy Chelkas Yoav ztz"l.
It says in the sefarim that when you learn the Torah of the Baal Hayahrtzeit, he is מליץ טוב for you in shomayim. We all need all the zchuyos we can get - so he goes....
The Ran [Chullin 58a] and Tosfos [Bava Kamma 47a] hold that עובר לאו ירך אמו - a fetus is halachically considered a separate entity from the mother and the reason a fetus that gored - ולד הנוגחת - is forbidden to go on the mizbeach [Sanhedrin 80] is NOT because it is ירך אמו but because the עובר participated in the act of goring, so it also becomes אסור למזבח.
In Bava Kamma [40b] there is a machlokes about a שור האצטדין - a bull fighting animal that gored. Rav says כשר למזבח because it is אנוס. The animal was instigated and is not at fault. Shmuel says פסול because an aveirah was done with this animal. We pasken like Rav that it is כשר because it was אנוס.
Asked the Chelkas Yoav [קבא דקשייתא סימן כ"ג]: Wait a minute. If a שור האצטדין is כשר למזבח because it is אנוס then a ולד הנוגחת should similarly be פטור becaue it is ALSO אנוס?? Is the fetus responsible for the goring of the mother??? I say NOT!
So why is ולד הנוגחת pasul for the mizbeach and not an אנוס while a שור האצטדין is considered אנוס??
מאי שנא??
