Leviticus 8:9 - Matthew Poole's English Annotations on the Holy Bible

This here added, either because Nadab and Abihu had been led to their error by drinking too much, which might easily fall out when they were feasting and full of joy for their entrance into so honourable and profitable an employment; or at least because others might thereby be drawn to commit the same miscarriages, which they might now commit from other causes. Drunkenness is so odious a sin in itself, especially a minister, and most of all in the time of his administration of sacred things, that God saw fit to prevent all occasions of it. And hence the devil, who is God's ape in his prescriptions for his worship, required this abstinence from his priests in their idolatrous service.