"Nadav" is the name of the eldest son of Aaron, the righteous priest.

Nadav and his brother Abiud, acting contrary to the Will of God, "brought a strange fire" into the service of God, i.e., instead of zealous, fervent, true service to the One God Jehovah, they introduced a false, ceremonial religious service to God, a false understanding and fulfillment of the Will of God.

 Nadab and Abiud "kindled," i.e., stirred up in the people a false religiosity with all its inherent manifestations: blind, fanatical faith, mysticism in understanding the sayings of Moses, religious superstition, pagan religious rites, and a desire for national exaltation and patriotism.