This was their appointed order for service when they entered the house of the LORD, according to the regulations prescribed for them by their forefather Aaron, as the LORD, the God of Israel, had commanded him.
KJV
These [were] the orderings of them in their service to come into the house of the LORD, according to their manner, under Aaron their father, as the LORD God of Israel had commanded him.
ASV
This was the ordering of them in their service, to come into the house of Jehovah according to the ordinance given unto them by Aaron their father, as Jehovah, the God of Israel, had commanded him.