After their victory over their Philistine enemies the soldiers in King Shauls army consecrated the animals they had taken as spoils to be sacrificed to G-d. In their haste to eat the meat of these sacrifices, however, they began dining on this meat before the blood was applied to the altar. When the king heard of this sinfulness he ordered a large stone to be brought to him which would serve as an altar, something which was permissible during the period that the Mishkan was in its temporary location in Nob. He then had an order announced to all of his men to bring their animals to him and "slaughter them thus" (Shmuel I 14:32-34).

The simple meaning of this phrase is that Shaul wanted them to slaughter the sacrifices next to his makeshift altar so that their blood could immediately be applied to that altar, following which it would be permissible to eat the meat. Rabbi Chisda, however, saw in this phrase not only an instruction where to carry out the slaughtering but also guidance in regard to the instrument used for the slaughter. "Slaughter them with this" is what Shaul included in his instructions as he handed the slaughterers a knife he had inspected to ascertain its halachic eligibility for slaughtering. This, concludes the Sage, is a Torah source for the rule that a shochet must show his slaughtering knife to a halachic authority before performing the shechita.

His revelation is modified, however, because of the statement of Rabbi Yochanan in an earlier gemara (Chullin 10b), that by Torah law there is no need for a rabbinical inspection of the shechita knife because the shochet himself is believed to certify that the knife was without any disqualifying flaw. It was only to give honor to the halachic authority that the Sages instituted the need for the shochet to seek his approval of the knifes eligibility. The account of Shauls inspection of the knives he handed over to his people for shechita serves as a hint from a Torah source for instituting this practice.

Chullin 17b

If the nape of the neck of a man is broken along with most of the flesh attached to it he is considered as dead, rendering anyone under the same roof ritually impure.

This determination by Rabbi Yehuda in the name of the Sage Shmuel that the status of death in this case depends on the severance of the flesh as well is challenged by the description we find of the death of the Kohen Gadol Eli. He was 98 years old and blind after 40 years of leading his people when war broke out with the Philistines. A refugee from the rout suffered by the Israelites on the battlefield delivered to him the terrible news of the losses suffered, including the death of Elis two sons. When he climaxed his alarming report with the news that the Holy Ark had been captured by the enemy, Eli was so overcome with grief that he fell backwards from his seat, broke his nape, and died (Shmuel I 4:15-18). Since all that is mentioned is the breaking of the nape it seems that death can be caused even without the severing of the flesh attached to it, counter to Shmuels ruling.

The response to this challenge is a reference to the advanced age of Eli mentioned in the above-cited passages. Since he was so old his death came about with the mere breaking of his nape even though the flesh attached remained intact. The simple understanding given by the commentaries of these passages stress on Elis age and the heaviness of his body is that these factors prevented him from breaking his fall. The gemara nevertheless also saw in his advanced age a contributing cause to an accident which would not have proved fatal to a younger man.