Contradiction with 1 Chronicles 25:1
1 Chronicles 26:21 talks about the Levitical service of the sons of Laadan, but 1 Chronicles 25:1 discusses the organization of singers, which is unrelated to the subject of 1 Chronicles 26:21.
1 Chronicles 25:1: Moreover David and the captains of the host separated to the service of the sons of Asaph, and of Heman, and of Jeduthun, who should prophesy with harps, with psalteries, and with cymbals: and the number of the workmen according to their service was:
Contradiction with Exodus 4:14
This verse mentions Aaron and his role, while 1 Chronicles 26:21 is about the duties of Levite gatekeepers, which doesn't align with Aaron's specific priestly duties.
Exodus 4:14: And the anger of the LORD was kindled against Moses, and he said, [Is] not Aaron the Levite thy brother? I know that he can speak well. And also, behold, he cometh forth to meet thee: and when he seeth thee, he will be glad in his heart.
Contradiction with Numbers 18:7
Numbers 18:7 details the priestly duties which were given to Aaron and his sons exclusively, whereas 1 Chronicles 26:21 speaks about Levites of the family of Laadan, not those appointed to priestly duties.
Numbers 18:7: Therefore thou and thy sons with thee shall keep your priest's office for every thing of the altar, and within the vail; and ye shall serve: I have given your priest's office [unto you] as a service of gift: and the stranger that cometh nigh shall be put to death.
Contradiction with Hebrews 7:12
This verse talks about a change in the priesthood, indicating the overall system changes, while 1 Chronicles introduces specific Levitical roles that don't reflect this change.
Hebrews 7:12: For the priesthood being changed, there is made of necessity a change also of the law.
Contradiction with Matthew 12:5
Matthew discusses priests working on the Sabbath without guilt, whereas 1 Chronicles 26:21 details the roles of non-priestly Levites, unrelated to Sabbath laws or practices.
Matthew 12:5: Or have ye not read in the law, how that on the sabbath days the priests in the temple profane the sabbath, and are blameless?