Bekhorot 39B

והאמר רבי זירא אמר רב: הצורם אזן הפר ואחר כך קיבל דמו ⁠— פסול, שנאמר ״ולקח מדם הפר״⁠ — הפר שהיה כבר! אלא: כאן שחסרה קודם קבלה, כאן שחסרה לאחר קבלה.

But doesn’t R' Zeira say that Rav says: In the case of one who slits the ear of the bull with the knife after slaughter, creating a blemish, and after that collects its blood from the neck, the offering is disqualified, as it is stated: “And the anointed priest should take from the blood of the bull” (Leviticus 4:5). By using the term “the bull,” the verse indicates that the bull must be at the time of collection of the blood as it already was before slaughter, without a blemish. Rather, here, in the first baraita, it is referring to a case where it lacked a kidney before the collection of the blood, whereas there, in the second baraita, it is dealing with a case where it lacked a kidney only after the collection of the blood.

ולאחר קבלה קודם זריקה, מי שרי? והתניא: ״שה תמים זכר בן שנה יהיה לכם״, שיהא תמים בן שנה בשעת שחיטה.

The Talmud asks: And if the animal lacked a kidney after the collection of the blood but before the sprinkling of the blood, is it permitted to be sacrificed upon the altar? But isn’t it taught in a baraita that the verse states with regard to the Paschal offering: “Your lamb should be without blemish, a male in its year” (Exodus 12:5), indicating that it should be unblemished and in its first year at the time of slaughter?

ומנין בקבלה והולכה והזייה? תלמוד לומר: ״יהיה״, שיהו כל הויותיו תם ובן שנה.

The baraita continues: And from where is it derived that it must also be unblemished at the time of the collection of the blood, and at the time of conveying its blood to the altar, and at the time of the sprinkling of the blood? The verse states: “should be,” emphasizing that all actions that are performed upon it should be performed only when it is unblemished and in its first year. This teaches that the offering must be unblemished even at the time of the sprinkling of its blood.