Yoma 63A

שחטן בחוץ קודם שנפתחו דלתות ההיכל ⁠— פטור. מאי טעמא: מחוסר פתיחה כמחוסר מעשה דמי.

Based on Rav Ḥisda’s statement, if he slaughtered them outside the Temple before the doors of the Sanctuary were opened he is exempt. What is the reason? Lacking the opening of the doors is comparable to lacking an action. Therefore, the offering was not yet fit to be sacrificed in the Temple, and when he slaughtered it outside, despite doing so with the intention that it is a sacrificial offering, he is not considered to have violated the prohibition against sacrificing an offering outside the Temple.

ומי אית ליה לרב חסדא ״הואיל״?

Rav Ḥisda stated above that since the Yom Kippur goats could be used for the additional offerings, one is liable for slaughtering them outside the Temple. The Talmud asks: Does Rav Ḥisda accept the principle: Since a particular situation could come to be in the future, it is viewed as though it existed already in the present?

והאמר רב חסדא: פסח ששחטו בחוץ בשאר ימות השנה, לשמו ⁠— פטור, שלא לשמו ⁠— חייב.

And didn’t Rav Ḥisda say: If one slaughtered a Paschal lamb outside the Temple during the rest of the days of the year other than Passover eve, if he slaughtered it for its own sake, i.e., as a Paschal lamb, he is exempt, since at that time it is not fit to be sacrificed as a Paschal lamb. If he sacrificed it not for its own sake but rather as a peace-offering, he is liable. A Paschal lamb that is slaughtered as a peace-offering on any day of the year other than Passover eve is considered a valid peace-offering. Therefore, it has the status of an offering that is fit to be sacrificed in the Temple, and he is liable for slaughtering it outside the Temple.