Gittin 65A

כעין דאורייתא תקון.

they instituted parallel to Torah law, and they did not innovate novel halakhic models.

ואידך ⁠– כי אמרינן: כל דתקון רבנן כעין דאורייתא תקון ⁠– במילתא דאית לה עיקר מן התורה, אבל מילתא דלית לה עיקר מן התורה ⁠– לא.

And the other Sage, Rav Ḥinnana of Vardonia, why was he silent? He holds that when we say: All ordinances that the rabbis instituted, they instituted parallel to Torah law, it is with regard to a matter that is rooted in the Torah, and upon which the rabbis instituted an ordinance. However, with regard to a matter that is not rooted in the Torah, e.g., the halakhot of joining courtyards and merging alleyways, no, they did not institute the ordinances parallel to Torah law.

מתיב רב אויא: מערימין על מעשר שני. כיצד? אומר אדם לבנו ובתו הגדולים; לעבדו ושפחתו העברים: ״הא לכם מעות הללו, ופדו בהן מעשר שני זה״, ואוכלו בלא חומש.

Rav Avya raises another objection to Shmuel’s opinion, according to Rav Ḥisda’s explanations, that a minor cannot acquire property on behalf of others, based on a Mishnah in tractate Ma’aser Sheni (4:4): One may employ artifice to exempt himself from the obligation to add 1/5th to the sum when redeeming second tithe, which the owner of the tithe is required to add. How so? A person says to his adult son or daughter, or to his Hebrew slave or his female slave: Here you are, take money and redeem second tithe with it. After they redeem the second tithe, they give it to their father or master and he eats it without adding 1/5th.

האי שפחה היכי דמי? אי דאתיא שתי שערות, מאי בעיא גביה? אלא לאו דלא אתיא שתי שערות? הכא במאי עסקינן, במעשר בזמן הזה ⁠– דרבנן.

The Talmud asks: What are the circumstances of this female slave? If she developed two pubic hairs, indicating that she reached majority, what is she doing with the owner of the produce? A Hebrew female slave is emancipated when she reaches puberty. Rather, is the reference here not to a case where she did not yet develop two pubic hairs? Apparently, a minor can also acquire property on behalf of others. The Talmud rejects this proof: With what are we dealing here? It is with tithes today, which is in effect by rabbinic law, and the rabbis ruled leniently in matters of rabbinic law.