from. from before.
devoured them. slew them; for they were not consumed, as is shown in Leviticus 10:4 and Leviticus 10:6. Note the three fires here: (1) the fire of true worship (Leviticus 9:24); (2) the strange fire of false worship (Leviticus 10:1); (3) the devouring fire of judgment (Leviticus 10:2).
died before the LORD: i.e. in the court of the sanctuary, where their sin had been committed.