Zevachim Daf 4 זבחים דַף 4

The Gemara asks: מנלן דבעינן זביחה לשמה – from where do we derive that shechitah must be לשמה? The passuk says: ואם זבח שלמים קרבנו – and if his offering is a sacrifice of shelamim. The word "זבח" teaches שתהא זביחה לשם [שלמים] – that the shechitah should be for the sake of a shelamim. The Gemara then brings pesukim requiring קבלה – receiving the blood, and זריקה – throwing the blood on the מזבח, to be done לשמה, and explains why none of these עבודות can be learned from each other. The Gemara then asks for the source that הולכה – bringing the blood to the מזבח must be done לשמה. This cannot be derived from the others, because they are each an avodah שאי אפשר לבטלה – that one cannot avoid, whereas הולכה can be avoided if one shechts near the מזבח. The Gemara quotes the passuk: והקריב...את הכל המזבחה – and he shall bring it all…on the mizbeiach, which refers to הולכת אברים לכבש – bringing the limbs to the ramp of the מזבח. Another passuk says "והקריבו" when referring to קבלת הדם, and used the term for הולכה to teach that הולכה must also be done לשמה.

Having derived the laws of שינוי קודש – a change of holiness regarding all עבודות (that they must be performed for the korban’s sake), the Gemara asks for the source for the laws of שינוי בעלים – a change of owner, i.e., that עבודות must be done for the owner’s sake. The passuk ובשר זבח תודת שלמיו – and the meat of the zevach todah which is his shelamim, teaches that the shechitah must be לשם תודה, and since שינוי קודש is already known, the passuk is used to teach שינוי בעלים. It then derives שינוי בעלים regarding the other עבודות, and the Gemara discusses multiple reasons that שינוי בעלים cannot be derived from שינוי קודש. After deriving that זריקה must also be for the owner’s sake, the Gemara derives all עבודות from a כלל ופרט וכלל, that just as shechitah is an עבודה and requires לשמן, so too all עבודות require לשמן. The laws of שינוי קודש and שינוי בעלים, which were taught by שלמים, are extended to all korbanos through a hekesh: זאת התורה לעולה ולמנחה ולחטאת ולאשם ולמילואים ולזבח השלמים. In this list of different types of korbanos, היקישן הכתוב לשלמים – the passuk compared them all to shelamim, requiring לשמה both regarding שינוי קודש and שינוי בעלים.

The Gemara asks that one should say that if a korban was shechted שלא לשמה, it should be completely פסול. The passuk says: מוצא שפתיך תשמור ועשית כאשר נדרת וגו' – what comes out of your lips you shall observe and perform, just as you vowed, etc. [a nedavah]. These contradictory terms of נדר and נדבה teach:  אם כמה שנדרת עשית יהא נדר – if you did as you vowed (and brought the korban לשמה), it will be a fulfillment of your neder, ואם לא נדבה יהא – but if not, rather, it was shechted שלא לשמה, it will be a nedavah (a donated korban aside from your neder). This proves that the korban remains valid (although it does not fulfill the owner’s obligation). The Gemara explains that both this derashah and the derashah of "זאת התורה" (requiring לשמה by all korbanos) are necessary. If the Torah had only written the first derashah, which commands “observing and performing” one’s word, we would not know that it refers specifically to לשמה. If the Torah had only written זאת התורה, one would think a korban would be disqualified when shechted שלא לשמה.