Contradiction with Numbers 4:2-3
These verses contradict Numbers 4:1 by specifying that the age range for service is from thirty to fifty years old, not any age.
Numbers 4:2-3: Take the sum of the sons of Kohath from among the sons of Levi, after their families, by the house of their fathers,
Contradiction with Numbers 1:3
This verse contradicts Numbers 4:1 as it lists the age for those eligible for war service as twenty years old and upward, differing from the Levites’ service age later described.
Numbers 1:3: From twenty years old and upward, all that are able to go forth to war in Israel: thou and Aaron shall number them by their armies.
Contradiction with 1 Chronicles 23:24-27
These verses contradict Numbers 4:1 by stating that David made a change in service age, beginning it at twenty years old instead of thirty.
1 Chronicles 23:24-27: These [were] the sons of Levi after the house of their fathers; [even] the chief of the fathers, as they were counted by number of names by their polls, that did the work for the service of the house of the LORD, from the age of twenty years and upward.
Contradiction with Numbers 8:24
This verse contradicts Numbers 4:1 by stating that the Levites begin their service at the age of twenty-five rather than thirty as described later again.
Numbers 8:24: This [is it] that [belongeth] unto the Levites: from twenty and five years old and upward they shall go in to wait upon the service of the tabernacle of the congregation: [to...: Heb. to war the warfare of, etc]