Pesachim 57A

נימא תלתא תנאי הוו? לא, תרי תנאי הוו, ותנא קמא דרבי שמעון היינו רבי יוסי, ותנא קמא דרבי יוסי היינו רבי שמעון. ומאי ״אף״⁠ — אקמייתא.

Let us say that there are 3 tanna’im who dispute this point: The two unattributed opinions, each of which is referring to two vegetables, and the opinion common to R' Yosei and R' Shimon that includes all 3 vegetables. The Talmud rejects this: No, there are only two tanna’im who dispute the point, and the first tanna whose opinion appears before the opinion of R' Shimon is R' Yosei. And the first tanna whose opinion appears before the opinion of R' Yosei is R' Shimon. And what is the meaning of the word even in both their statements? They agree with regard to the first vegetable, turnips; however, they disagree with regard to the second, and replace it with another vegetable.

תנו רבנן: בן בוהיין נתן פיאה לירק, ובא אביו ומצאן לעניים שהיו טעונין ירק ועומדין על פתח הגינה. אמר להם: בני, השליכו מעליכם ואני נותן לכם כפליים במעושר. לא מפני שעיני צרה, אלא מפני שאמרו חכמים: אין נותנין פיאה לירק.

The Talmud cites an episode from the Tosefta. A baraita states: The son of a man named Bohayan designated for the poor the produce in the corner in a garden of vegetables, and his father Bohayan found the poor laden with vegetables and standing at the opening of the garden on their way out. He said to them: My sons, cast the vegetables that you have gathered from upon yourselves and I will give you twice the amount in tithed produce, and you will be no worse off. Not because I begrudge you what you have taken. Rather, it is because the rabbis say: One does not designate for the poor the produce in the corner in a garden of vegetables. Therefore, the vegetables that you took require tithing.