Charles Ellicott Commentary Leviticus 10:19

"And Aaron spake unto Moses, Behold, this day have they offered their sin-offering and their burnt-offering before Jehovah; and there have befallen me such things as these: and if I had eaten the sin-offering to-day, would it have been well-pleasing in the sight of Jehovah?" — Leviticus 10:19 (ASV)

And Aaron said.—Although, according to Leviticus 10:16, Moses only blamed Eleazar and Ithamar for this transgression of the law, there can hardly be any doubt that Aaron was included in this censure, and that the lawgiver abstained from expressing his anger against the high priest because of the supreme dignity of his office, which he would not lower in the sight of the people. Aaron, however, was fully aware of this, and therefore replies to the charge brought against his sons.

They offered their sin offering.—Before proceeding to the transgression with which they are thus charged, Aaron refers to the fact that all the other sacrificial duties in which he and his sons were engaged on the same day, before the great calamity, were performed in strict accordance with the prescribed ritual. His sons, assisting him, had offered “their”—i.e., the people’s—sin and burnt offerings up to this point in proper compliance with the requirements of the law, and therefore could never have meant to transgress intentionally.

And such things have befallen me.—But while he, Eleazar, and Ithamar were thus properly performing the sacrificial rites, Nadab and Abihu, his other two sons, transgressed and were suddenly struck down dead. This overwhelmed the survivors with sorrow and rendered them unfit to partake of the sacrifices.

And if I had eaten.—Aaron submits that, since they were thus unfitted by mourning and the sense of their own sinfulness, if they had partaken of this solemn meal, it would not have been acceptable to the Lord. In consequence of this declaration, the rule was established during the Second Temple period that when an ordinary priest heard of the death of a relative while on duty in the sanctuary, he had to cease from service. However, he could not leave the precincts of the Temple, as he would otherwise defile the sacrifice. Meanwhile, the high priest, who could continue his sacred ministrations, was not allowed to partake of the sacrificial meal.