- שאור of חולין and תרומה which fell into dough and leavened it
The Gemara suggests that the question of זה וזה גורם is a machlokes between Rebbe Eliezer and the Rabbonon. A Mishnah states: שאור של חולין ושל תרומה שנפלו לתוך העיסה – if leaven of chullin and leaven of terumah fall into a dough, and neither was sufficient to leaven the dough on its own, but they combined to leaven the dough, Rebbe Eliezer says: אחר האחרון אני בא – I follow the last one (if the chullin fell in second, the entire dough is permitted to non-Kohanim; if the terumah fell in second, it is prohibited to non-Kohanim). The Chochomim say that regardless of when the forbidden שאור fell in, it only prohibits the dough if it was enough to leaven the dough by itself. Abaye said that Rebbe Eliezer only permits the dough if the איסור was removed before the permitted שאור fell in (so the permitted שאור completed the leavening alone), אבל לא קדם וסילק את האיסור אסור – but if he did not remove the forbidden שאור before the permitted שאור fell in, [the dough] is prohibited, because they leavened the dough together. We see that Rebbe Eliezer holds זה וזה גורם אסור. However, the Gemara questions Abaye’s interpretation, and suggests that even if the איסור was not removed, Rebbe Eliezer would permit the dough if the permitted שאור fell in last.
- Avoiding benefit from avodah zarah by throwing away its value
The next Mishnah states that wood taken from an אשרה is forbidden in benefit. If one fired up an oven with it, if this firing completed a new oven’s hardening, it must be destroyed (because any subsequent use benefits from this necessary firing). ואם ישן יוצן – If it is old, it must be cooled to avoid benefiting from the firing, and may be used afterwards. Any bread baked in a forbidden oven is prohibited in benefit (because this Mishnah holds זה וזה גורם אסור), and if it became mixed with other bread, they are all prohibited. Rebbe Eliezer says: יוליך הנאה לים המלח – he may throw the value of the forbidden benefit into the Dead Sea, and the bread becomes permitted. However, the Rabbonon said to him: אין פדיון לעבודת כוכבים – there is no redemption for idolatrous items, and they do not become permitted by throwing away the benefit’s value. The same machlokes is taught regarding a garment woven from a weaver’s tool fashioned from an אשרה. This garment is forbidden in benefit, and if it became mixed with other garments, they are all prohibited. Amoraim debate if Rebbe Eliezer’s resolution applies even to חבית – a barrel of יין נסך which became mixed with permitted barrels, since the forbidden substance is physically in the mixture.
- The shavings of an אשרה which were shaved off for the אשרה’s needs
The next Mishnah teaches that one nullifies an אשרה if he pruned or trimmed it (to use the trimmings for his own purposes), or even if he removed a stick, twig, or leaf from it. שיפה לצרכה אסורה – If he shaved off chips for its own purposes (e.g., to beautify it), it is still forbidden; שלא לצרכה מותרת – if he shaved them off not for its needs, it is permitted. The Gemara asks: אותן שפאין מה תהא עליהן – what it the law with those chips which were removed for the אשרה’s benefit? Do they remain prohibited like the אשרה, or are they permitted, because shavings are not worshipped? Rav Huna and Chiya brei d’Rav disagreed about this question, and a Baraisa supports the lenient opinion.