The roles and responsibilities of the priests and Levites are foundational to the religious and communal life of ancient Israel, as outlined in the Old Testament. These duties were divinely ordained and were integral to the worship and sacrificial system established by God through Moses.

Priests:

The priesthood was established through Aaron, the brother of Moses, and his descendants. The primary duties of the priests included offering sacrifices, maintaining the sanctuary, and teaching the people the laws of God. The priests acted as mediators between God and the Israelites, performing rituals that were essential for atonement and worship.

1. Sacrificial Duties: The priests were responsible for offering various sacrifices on behalf of the people. These included burnt offerings, sin offerings, and peace offerings, among others. Leviticus 1-7 provides detailed instructions on how these sacrifices were to be conducted. The priests ensured that the offerings were made according to God's commands, maintaining the sanctity of the sacrificial system.

2. Maintaining the Sanctuary: The priests were charged with the care of the Tabernacle, and later the Temple. This included ensuring that the sacred space was kept holy and that all rituals were performed correctly. They were responsible for the upkeep of the altar, the lampstand, and other sacred objects (Exodus 27:20-21).

3. Teaching and Judging: Priests were also tasked with teaching the Israelites God's laws and statutes. They served as judges in certain legal matters, providing guidance based on the Law. Deuteronomy 17:9-11 emphasizes their role in interpreting the law and making judicial decisions.

4. Blessing the People: One of the priestly functions was to pronounce blessings upon the people. The Aaronic blessing, found in Numbers 6:24-26, is a well-known example of this duty.

Levites:

The Levites, from the tribe of Levi, were set apart to assist the priests and perform various functions related to the Tabernacle and Temple service. Unlike the priests, the Levites did not perform sacrifices but had their own distinct roles.

1. Assisting the Priests: The Levites were responsible for assisting the priests in their duties. This included preparing the offerings, maintaining the sacred vessels, and ensuring the smooth operation of the worship services (Numbers 3:5-9).

2. Guarding the Tabernacle: The Levites were tasked with guarding the Tabernacle and later the Temple. They ensured that only authorized individuals entered the sacred spaces, thus protecting the holiness of the sanctuary (Numbers 1:50-53).

3. Transporting the Tabernacle: During the Israelites' wilderness wanderings, the Levites were responsible for dismantling, transporting, and reassembling the Tabernacle. Each Levitical family had specific duties related to the transport of the Tabernacle's components (Numbers 4:1-33).

4. Musical and Worship Roles: The Levites also played a significant role in the musical aspects of worship. They were involved in singing, playing instruments, and leading the congregation in praise and worship, especially during the time of King David (1 Chronicles 15:16-22).

The division of duties among the priests and Levites ensured that the worship of God was conducted in an orderly and reverent manner, reflecting the holiness and majesty of God. These roles were not only functional but also symbolic, pointing to the need for mediation and holiness in approaching God.