On account of the sin of Levi and Simeon (Genesis 34:1–31), their descendants were cursed by Jacob and destined to be scattered amongst the tribes of Israel (Genesis 49:5–7). This is one of the reasons why neither Levi nor Simeon received land but only cities (see Joshua 19:1–9). The descendants of Levi, however, redeemed themselves. Where the rest of their brothers bowed to worship the golden calf, they rallied to Moses and acted in a way that honoured God (Exodus 32:25–29). The same devotion to the Lord was seen in the example of Phinehas (Numbers 25:6–8).1 Though the descendants of Aaron were chosen to serve as priests even before the golden calf incident (Exodus 28:1 – 29:46), the actions of the Levites at the foot of Mount Sinai may also have had an influence on the Levites being appointed as teachers of the law (Deuteronomy 33:10). The explicit reason given by Scripture as to why the Levites were chosen to serve the Lord at the temple is that the Levites took the place of the firstborn (Numbers 3:11–13).
As a result of the Levites having been chosen by God, all the Levites were given the task of acting as teachers and interpreters of God’s law (Deuteronomy 33:10; see 2 Chronicles 17:7–9; 2 Chronicles 35:3; Malachi 2:6–9; Nehemiah 8:7–8). With the Levites being scattered amongst the tribes, they would be able to ensure that God’s law is taught throughout the land, serving as salt and light amongst their fellow Israelites.2
1 Then the heads of the fathers’ houses of the Levites came to Eleazar the priest and to Joshua the son of Nun and to the heads of the fathers’ houses of the tribes of the people of Israel.