Beitzah 22B

מה שאין כן בביצה!

which is not so with regard to an egg. With regard to an egg laid on a Festival, the two days of Rosh HaShana are considered one long day and a single period of sanctity. It was only in deference to the dead that the rabbis were lenient with regard to burial on the 2nd day of Rosh HaShana, but with regard to all other matters, the two days of Rosh HaShana are viewed as one day and are governed by the same halakha.

אמר ליה: אנא כנהרדעי סבירא לי, דאמרי אף בביצה. ומאי דעתיך ⁠— דלמא מעברי ליה לאלול? האמר רב חיננא בר כהנא: מימות עזרא ואילך לא מצינו אלול מעובר.

Ameimar said to him: I hold in accordance with the opinion of the rabbis of Neharde’a, who state this halakha even with regard to an egg laid on the Festival and other matters, as there is no difference between the two days of Rosh HaShana and the two days of other Festivals. And what is your reasoning that you are concerned? Is it that perhaps they will extend the month of Elul and declare it a 30-day month, which would mean that the 2nd day of the Festival is the 1st of Tishrei, the true date of Rosh HaShana? But didn’t Rav Ḥinnana bar Kahana say: From the days of Ezra and onward we have not found that the month of Elul was made a full, 30-day month, and therefore there is no cause for this concern.

ואין אופין פתין גריצין אלא רקיקין. תנו רבנן, בית שמאי אומרים: אין אופין פת עבה בפסח, ובית הלל מתירין. וכמה פת עבה ⁠— אמר רב הונא: טפח. שכן מצינו בלחם הפנים, טפח.

§ It is taught in the Mishnah: And one may not bake thick loaves on a Festival but only thin ones. A baraita states the following baraita: Beit Shammai say that one may not bake thick bread on Passover, as it might become leavened before it has a chance to bake, whereas Beit Hillel permit it. And how much thickness renders a loaf thick bread that is permitted by Beit Hillel? Rav Huna said: It is up to a thickness of one handbreadth, as we find likewise with regard to the showbread in the Temple, which must also be unleavened and which was one handbreadth thick.