Numbers 3 and 4 are various lists concerning the Levite priests and their specific roles. Three sons of Levi, Gershon, Kohath, and Merari were responsible for moving and maintaining the components of the tabernacle.
They were not to be soldiers. The firstborn of the Levites especially belonged to God. Their priesthood was to begin at age 30 and end at 50. Notice that Joseph came to power in Egypt at age 30, David became king at 30, and Jesus Christ began his ministry on Earth at 30 years old.
Once again, the prophetic knowledge from God is shown through the writings of Moses. Unfortunately, there really is not much else that jumps out at me in these passages.
Simmons' Opinions 