Berakhot 39A

בצר ליה שיעורא.

it lacks the requisite measure? The smallest quantity of food that is considered eating is the size of an olive-bulk, and an olive with its pit removed is smaller than that.

אמר ליה: מי סברת כזית גדול בעינן? כזית בינוני בעינן (והא איכא), וההוא דאייתו לקמיה דרבי יוחנן זית גדול הוה, דאף על גב דשקלוה לגרעינותיה פש ליה שיעורא.

He said to him: Do you hold that we require a large olive as the measure of food necessary in order to recite a blessing after eating? We require a medium-sized olive and that olive was that size, as the olive that they brought before R' Yoḥanan was a large olive. Even though they removed its pit, the requisite measure remained.

דתנן: זית שאמרו לא קטן ולא גדול, אלא בינוני ⁠— וזהו ״אגורי״. ואמר רבי אבהו: לא ״אגורי״ שמו אלא ״אברוטי״ שמו, ואמרי לה ״סמרוסי״ שמו. ולמה נקרא שמו ״אגורי״⁠ — ששמנו אגור בתוכו.

The Talmud cites a proof that the halakhic measure of an olive is not based on a large olive as we learned in a Mishnah: The olive of which the rabbis spoke with regard to the halakhic measures is neither small nor large, but medium, and that olive is called aguri. And R' Abbahu said: The name of that genus of olives is not aguri, but its name is avruti, and some say that its name is samrusi. And why, then, is it called aguri? Because its oil is accumulated [agur] inside it.

נימא כתנאי: דהנהו תרי תלמידי דהוו יתבי קמיה דבר קפרא. הביאו לפניו כרוב ודורמסקין ופרגיות. נתן בר קפרא רשות לאחד מהן לברך, קפץ וברך על הפרגיות. לגלג עליו חבירו. כעס בר קפרא אמר: לא על המברך אני כועס, אלא על המלגלג אני כועס. אם חבירך דומה כמי שלא טעם טעם בשר מעולם, אתה על מה לגלגת עליו? חזר ואמר: לא על המלגלג אני כועס, אלא על המברך אני כועס. ואמר: אם חכמה אין כאן, זקנה אין כאן?!

With regard to the appropriate blessing over boiled vegetables: Let us say that this dispute is parallel to a dispute between the tanna’im, as the Talmud relates: Two students were sitting before bar Kappara when cooked cabbage, cooked Damascene plums and pullets were set before him. Bar Kappara gave one of the students permission to recite a blessing. He hurried and recited a blessing over the pullets and his counterpart ridiculed him for gluttonously reciting the blessing that should have been recited later, first. Bar Kappara became angry with both of them, he said: I am not angry with the one who recited the blessing, but at the one who ridiculed him. If your counterpart is like one who never tasted the flavor of meat and was therefore partial to the pullet, and hurriedly ate it, why did you ridicule him? Bar Kappara continued and said to the second student: I am not upset at the one who ridiculed him, rather it is with the one who recited the blessing that I am angry. And he said: If there is no wisdom here, is there no elder here? If you are uncertain which blessing to recite first, couldn’t you have asked me, as I am an elder?