en_tn_condensed/2ch/29/34.md

to skin all the burnt offerings

"to remove the skins from all the burn offerings"

until the work was done

This can be stated in active form. AT: "until they had finished the work" (See: rc://en/ta/man/translate/figs-activepassive)

until the priests could consecrate themselves

Since there were some priests who were already consecrated, this implies that more priests consecrated themselves. AT: "until more of the priests could consecrate themselves" (See: rc://en/ta/man/translate/figs-explicit)

had been more careful to consecrate themselves

There were enough Levites to do this work because they had been careful to consecrate themselves. This implies that the reason that there were not enough priests was because the priests were not careful to consecrate themselves.