Leviticus — Chapter 10

Nadab and Abihu, sons of Aaron, offering strange fire before the Lord, were consumed. Lapide teaches that this was a figure of the death of heretics who offer worship not according to divine institution. The fire was \"strange\" because it was not taken from the altar of holocausts as God commanded, but was self-chosen worship. As St. Ambrose says: it is impiety to introduce new rites into the liturgy uninstructed by divine authority.

God said: \"I will be sanctified in them that approach me, and before all the people I will be glorified\" (Lev. 10:3). Lapide notes this is the foundational principle of the liturgy: the service of God must be performed with the utmost reverence and fidelity to divine institution, lest what is meant to glorify Him becomes an occasion of irreverence. Moses comforted Aaron who grieved silently — a model of priestly submission to the will of God even in desolation.

Aaron and his sons are forbidden to drink wine or strong drink when they enter the tabernacle (Lev. 10:9). Lapide: this law has never been formally abrogated but its literal observance was accommodated by the Church, which uses wine in the Eucharist by divine command. The spirit of the law endures: the priest must approach the holy mysteries with a sober and recollected mind, free from the disturbance of passion, intemperance, or worldly preoccupation. Drunkenness in a priest is doubly sinful: against temperance and against priestly dignity.

God commands Aaron: \"That you may have knowledge to discern between the holy and the unholy, and between the unclean and the clean\" (Lev. 10:10-11). Lapide: the primary duty of the priest is to be a doctor of the law — to distinguish sacred from profane, clean from unclean, lawful from unlawful — and to teach the children of Israel. This passage is the Mosaic warrant for the Church's magisterium: the priest/bishop as teacher of truth and guardian of the sacred.

Moses rebuked Eleazar and Ithamar for failing to eat the sin-offering in the holy place (Lev. 10:17-18). Lapide: the priest must consume the sin-offering because he \"bears the iniquity of the congregation\" — he participates in the expiatory function of the sacrifice by eating it. In the New Law, the priest consumes the Eucharist for the same reason: the complete sacrifice requires both the immolation and the sacerdotal consumption. This is why the Church teaches that the priest must always communicate at Mass.