Leviticus 10 records the tragic and immediate judgment of Nadab and Abihu, Aaron's oldest sons, for offering “unauthorized fire” before the Lord. This shocking event underscores the absolute holiness of God and the strict requirements for approaching Him in worship, especially for priests. The chapter continues with Moses instructing Aaron and his remaining sons on the proper conduct of their priestly duties, including the consumption of sacrificial portions, emphasizing the gravity of their role and the consequences of disobedience.