- "An earthenware vessel in which it was cooked shall be broken" (Vayikra 6:21)
Rashi explains that the reason for this is that the absorbed meat becomes "notar"(flesh from an offering which remains uneaten after the designated time),
When a vessel is not used for more then 24 hours, whatever is absorbed becomes pagum(spoiled). So why can't we use this vessel after 24 hours?
Pirkei Avos lists the miracles that took place in the Beis HaMikdash. One of these miracles was that "the meat of the sacrifices never spoiled." Therefore, the absorption in the vessel was always fresh, and since earthenware vessels can't be made kosher, the meat remains "notar" and the vessel can never be used.
- "And Aharon and his sons did all the things which G-d commanded through Moshe." Vayikra 8:36
Often, when a person is asked to be a shliach tzibur or deliver a Torah thought, he humbly shakes his head, expressing a sense of unworthiness. By moving his head to the left and right he is saying, "Who am I to perform such an important task?"
The praise of Aharon and his children, therefore, was that when they received a command, they immediately set out to do it without moving their heads "to the right and left," demonstrating pseudo-humility and expecting to be prevailed upon a second time.