Nedarim 58B

המנכש עם הכותי בחסיות ⁠— אוכל מהן אכילת עראי, ומעשרן ודאי.

One who weeds ḥasayot with a Samaritan may eat a casual meal from them without tithing, as any untithed produce may be eaten in the framework of a casual meal. And when he completes the labor on the ḥasayot, places them into a pile, and they require tithing, he tithes them as produce that is definitely obligated in tithing, not as doubtfully tithed produce, as the assumption is that the Samaritan did not tithe the ḥasayot.

רבי שמעון בן אלעזר אומר: אם ישראל חשוד על השביעית, למוצאי שביעית ⁠— מותר. למימרא דגידולי היתר מעלין את האיסור, ודלמא בדבר שזרעו כלה? הא תניא: אלו הן חסיות ⁠— כגון הלוף השום והבצלים.

R' Shimon ben Elazar says: If the ḥasayot belong to a Jew who is suspect about observance of the Sabbatical Year, at the conclusion of the Sabbatical Year it is permitted to weed with him, as there is no concern that there might be Sabbatical-Year sanctity. The Talmud asks: Is this to say that the permitted growths of the 8th year neutralize the prohibition, and that is why there is no concern about Sabbatical-Year sanctity? The Talmud rejects that inference: And perhaps the tanna is speaking with regard to an item whose seeds cease after it is sown, whose growths neutralize the original prohibition? The Talmud rejects that possibility: Isn’t it taught in a baraita: These are ḥasayot, For example: arum, garlic, and onions, whose seeds do not cease?

ודלמא במדוכנין? ״חשוד על השביעית״ קתני. ודלמא בתערובת? המנכש קתני.

The Talmud asks: And perhaps the tanna is speaking with regard to plants that were crushed before they sprouted growths? The Talmud answers: It is the case of one who is suspect about observance of the Sabbatical Year, that is taught in the baraita, and one who is suspect would not bother to eliminate the prohibition by crushing it. The Talmud asks: And perhaps the tanna is speaking with regard to a mixture of forbidden ḥasayot and permitted ones, and the reason that it is permitted is that the prohibition was neutralized by the majority of permitted ḥasayot? The Talmud answers: One who weeds, is taught in the baraita, indicating that he is eating the leaves as he weeds them, leaving no opportunity for the ḥasayot to be mixed with others.