In the biblical books Exodus, Leviticus and Numbers, Nadab (Hebrew: נָדָב, Modern: Nadav, Tiberian: Nāḏāḇ, "generous") and Abihu (Hebrew: אֲבִיהוּא, Modern: ʾAvīhūʾ, Tiberian: ʾĂḇīhūʾ, "my father [is] he") were the two oldest sons of Aaron.[1] According to Leviticus 10, they offered a sacrifice with "foreign fire" before the LORD, disobeying his instructions, and were immediately consumed by God's fire.
Moses instructed Aaron and his family not to mourn, although the people at large were permitted.[2]