§ Rav Ḥisda said that Rav said: If the head of his father, or any other relative for whom a priest becomes impure, was severed, he may not become impure to bury him. What is the reason for this? The verse states: “None shall become impure for the dead among his people, except…for his father” (Leviticus 21:1–2), which indicates that this applies when his father is whole, and not when he is lacking. Rav Hamnuna said to Rav Ḥisda: If that is so, then in a case where one was walking in the valley [pakta] of Aravot, a place frequented by bandits, and robbers severed his head, will you also say that his son the priest does not become impure to bury him because he is not whole?

Rav Ḥisda said to him: Do you speak of a corpse with no one to bury it [met mitzva]? This halakha certainly does not apply to a case of this kind. For now consider, if one can say that to bury others, i.e., non-relatives, he is obligated to become ritually impure, as even priests and nazirites must become impure to bury an unattended corpse, then with regard to a met mitzva who is his father is it not all the more so the case that he must become impure to bury him even if his head is severed?

The Gemara asks: And is this a met mitzva? But isn’t it taught in a baraita: Which is a met mitzva for whom a priest must become impure? It is anyone who does not have people to bury him apart from this priest. If the corpse is in a place where if he would call, others would answer him, that is not considered a met mitzva. And if this dead father has a son who was with him, it means the father is not classified as a met mitzva, and therefore his son the priest must ensure that others tend to his burial, without doing so himself. The Gemara answers: Since he was walking along the way, he is considered like one who does not have people to bury him.

The Gemara raises an objection against Rav Ḥisda’s opinion. The superfluous term “for her” in the verse “And for his sister a virgin who is near to him, who has no husband, for her he becomes impure” (Leviticus 21:3) teaches that it is to bury her in her whole state that he becomes impure, but he does not become impure to bury her limbs. If a limb was severed from her during her lifetime he does not tend to it, because he may not become impure to bury a limb severed from one of his living relatives, including that of his father. However, he may search for a bone that is a barley-grain-bulk. If he was already impure from his father’s body, he may search for and bury a bone that was detached from the corpse, even if it is large enough to impart impurity itself.

The Gemara asks: What is the meaning of: He may search for a bone that is a barley-grain-bulk? Isn’t this to say that if the deceased father is lacking a small part, i.e., a single bone, his son the priest becomes impure to bury him? This would contradict Rav Ḥisda’s statement in the name of Rav that he becomes impure to bury his father only if he is whole.

The Gemara answers: No, this presents no difficulty, as that baraita is in accordance with the opinion of Rabbi Yehuda. As it is taught in a baraita that Rabbi Yehuda says: “For her he becomes impure” (Leviticus 21:3), this indicates that to bury her he becomes impure but he does not become impure to bury her limbs, as he does not become impure to bury a limb severed from one of his living relatives, including that of his father. However, he does become impure to bury a limb from his dead father. Rav Ḥisda disagrees with the opinion of Rabbi Yehuda and rules in accordance with the Rabbis, who maintain that a priest may become impure only to bury his relative’s whole body.

The Gemara asks: But isn’t it taught in a baraita that Rav Kahana, son of Rabbi Eliezer ben Ya’akov, said: The words “for her he becomes impure” (Leviticus 21:3) indicate that to bury her he becomes impure when she is whole, but he does not become impure to bury her limbs. This serves to exclude an olive-bulk of solid material from a corpse, and an olive-bulk of fluid from a corpse, and a full spade of dust from a corpse.

One might have thought that he may not become impure for a spine and a skull, or for most of the skeleton or most of the number of bones from his sister’s corpse. Therefore, it is written at the beginning of this passage dealing with the impurity of priests: “Speak to the priests, the sons of Aaron, and say to them” (Leviticus 21:1). The repetition of “speak” and “say” indicates that the verse added a different form of impurity permitted to a priest.