Pesachim 84B

האי פסול. למאן דאמר ראוי לאכילה ⁠— האי נמי ראוי לאכילה הוא.

this one is disqualified, and the prohibition does not apply. However, according to the one who says that it depends on whether the offering is fit for eating, this offering that is brought in a state of ritual impurity is also fit for eating, and the prohibition of breaking a bone therefore applies.

רב יוסף אמר: כי האי גוונא ⁠— דכולי עלמא אין בו משום שבירת העצם, דרבי לאקולי קא אתי, והאי הא פסול הוא.

Rav Yosef said: In a case like this, in which the Paschal lamb was brought in a state of ritual impurity, everyone agrees that it is not subject to the prohibition of breaking a bone. This is because R' Yehuda HaNasi only came to be lenient, and this offering is disqualified due to the fact that it is ritually impure, despite the fact that such an offering is accepted and therefore obligatory.

אלא, היתה לו שעת הכושר ונפסל איכא בינייהו. למאן דאמר כשר ⁠— הא כשר הוא. למאן דאמר ראוי לאכילה ⁠— הא השתא לאו ראוי לאכילה הוא.

Rather, the practical difference between them is with regard to a Paschal lamb that had a time when it was valid and then became disqualified. According to the one who says that the verse should be understood as indicating that the prohibition of breaking a bone applies only to a valid Paschal lamb, this one is valid and the prohibition applies. According to the one who says that the prohibition applies only to an offering that is fit for eating, it is not fit for eating now, and therefore the prohibition does not apply.

אביי אמר: כולי עלמא כל כי האי גוונא אין בו משום שבירת העצם, מאי טעמא? השתא מיהת הא פסול הוא. אלא, שבירת העצם מבעוד יום איכא בינייהו. למאן דאמר כשר ⁠— הא כשר הוא, למאן דאמר ראוי לאכילה ⁠— השתא לאו בר אכילה הוא,

Abaye said: In any case like this, everyone agrees that it is not subject to the prohibition of breaking a bone. What is the reason? Now, at least, it is disqualified. Rather, the halakha with regard to breaking a bone while it is still day on Passover eve is the practical difference between them. According to the one who says the verse should be understood as applying the prohibition to any Paschal lamb that is valid, this one is valid and the prohibition applies. According to the one who says the prohibition applies to a Paschal lamb that is fit for eating, now it is not fit for eating and therefore the prohibition does not yet apply.