Beitzah 34A

שצריך לבדקן. ואמרי לה: מפני שצריך לחסמן.

it is necessary to test them to ensure that they do not burst when heated. If they are heated for the first time on a Festival, he will be thereby testing them, which is a prohibited labor. And some say: Because it is necessary to harden them by overheating them the first time to make them fit for use, which is considered preparing a vessel for use and is prohibited on a Festival.

תנן התם: דרסה או שטרפה בכותל, או שרצצתה בהמה ומפרכסת, ושהתה מעת לעת ושחטה ⁠— כשרה. אמר רבי אלעזר בר ינאי משום רבי אלעזר בן אנטיגנוס: צריכה בדיקה.

In relation to the above, the Talmud cites the following teaching: We learned in a Mishnah there: If one trampled fowl with his foot, or threw it against a wall, or if an animal crushed it, and it is twitching but cannot stand; if the animal waited, i.e., remained alive, from the time of the injury until the same time 24 hours later, and he subsequently slaughtered it, it is kosher, provided no other defect is found in it that would have caused it to die within 12 months, which would render it a tereifa. R' Elazar bar Yannai said in the name of R' Elazar ben Antigonus: It requires examination after slaughtering, to make sure it does not have a defect.

בעא מיניה רבי ירמיה מרבי זירא: מהו לשחטה ביום טוב? מי מחזקינן רעותא ביום טוב, או לא?

In relation to the same issue, R' Yirmeya inquired of R' Zeira: What is the halakha with regard to slaughtering it on a Festival? Do we assume on a Festival that it has a flaw or not? In other words, may one rely on the assumption that a typical chicken has no defect? Or perhaps, since there is concern with regard to this particular bird and it requires examination, one should refrain from slaughtering it lest it turn out to be a tereifa. If so, he will have performed labor for no purpose.