In this week’s parshah we read about the berachos that Yitzchak had intended to give Eisav, but instead (unintentionally) gave to Yaakov Avinu. Yaakov was able to receive the berachos instead of Eisav because Yitzchak had requested Eisav to go out to the field and hunt game for him. This provided Yaakov sufficient time to prepare everything in order for him to receive the berachos. When Yitzchak requested of Eisav that he hunt game for him, he told him to “…sa na keilecha telyecha vekashtecha – sharpen your gear, your sword, and your bow” (Bereishis 27:3). Rashi explains that Yitzchak was telling Eisav to sharpen his knife so that he would shecht (slaughter) properly; thus the food would not be a neveilah. The Sifsei Chachamim explains that by sharpening his knife he would ensure that there were not any nicks on the knife. Regarding this pasuk, the ba’alei Tosafos and the Rush add that the word in the pasuk, “tzayid,” is written with the letter “hay” although it is not pronounced. This is to inform us that Yitzchak taught Eisav the five (the numerical value of the letter “hay”) halachos of shechitah that can disqualify a shechitah.
The Chasam Sofer (She’eilos U’teshuvos, Yoreh De’ah 15) asks the following question regarding Yitzchak’s request to Eisav: Why did Yitzchak have to tell Eisav to sharpen his knife now? For if Yitzchak was indeed concerned that Eisav would otherwise not have sharpened his knife, how could he trust him now? And if Yitzchak felt confident that Eisav would generally check his knife, why was he compelled to remind him now? Similarly, one could ask why Yitzchak would now teach Eisav about hilchos shechitah. Shouldn’t he have taught him many years earlier, as Eisav was already 63 years old at the time of the berachos? Additionally, the ba’alei Tosafos ask another question on this episode. The Gemara in Chullin 5a says that a mumar (heretic) is unfit to shecht. How then could Yitzchak have eaten from Eisav’s shechitah, since the Gemara in Kiddushin 18a says that Eisav was a mumar?
As a result of this and other questions, the Chasam Sofer disagrees with the Sifsei Chachamim, saying that Yitzchak told Eisav to sharpen his blade for a different reason other than to ensure that it did not contain nicks. He explains that the purpose of telling Eisav to sharpen his knife was to remove the fat that was remaining on the knife from the avodah zarah foods that Eisav’s wives would serve. Generally this would not have prohibited the meat if it was rinsed, but since Yitzchak had asked for tzeli (roasted meat), as it was a korban Pesach, the meat would otherwise be prohibited unless the knife was cleaned via sharpening.
I would like to suggest the following solution to explain the opinion of the Sifsei Chachamim: The Gemara in Chullin 4a says that there are two types of mumars: a mumar leteiavon – one who sins out of temptation – and a mumar lehachis – one who sins without temptation but solely to spite Hashem. The halacha that a mumar is disqualified from shechting only applies to a mumar lehachis. A mumar leteiavon may shecht, provided that a trustworthy person checks his knife. In order to shecht properly there must not be any nicks on the blade of the knife. If there is, the shechitah is invalid. Therefore one must carefully check the blade prior to shechting, to ensure that there are no nicks on the blade. Since the process of checking the blade is burdensome, we may not rely on a mumar leteiavon exerting himself and checking his knife properly. Thus if a mumar leteiavon shechts without anyone checking his blade for him, the shechitah is invalid – for we assume that he did not properly check his blade and there may have been a nick on it. However, if someone else checks the blade, a mumar leteiavon may shecht.