Contradiction with Exodus 30:9
Exodus 30:9 forbids offering strange incense, whereas Numbers 16:6 involves taking censers, possibly leading to unauthorized incense offerings.
Exodus 30:9: Ye shall offer no strange incense thereon, nor burnt sacrifice, nor meat offering; neither shall ye pour drink offering thereon.
Contradiction with Leviticus 10:1
Leviticus 10:1 describes Nadab and Abihu offering strange fire before the Lord and being punished, contradicting the implied permissibility of approaching God with censers in Numbers 16:6.
Leviticus 10:1: And Nadab and Abihu, the sons of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered strange fire before the LORD, which he commanded them not.
Contradiction with 1 Samuel 13:12-13
In 1 Samuel 13:12-13, Saul is punished for offering a burnt offering instead of waiting for Samuel, contrasting with the apparent acceptance of laying actions in Numbers 16:6.
1 Samuel 13:12-13: Therefore said I, The Philistines will come down now upon me to Gilgal, and I have not made supplication unto the LORD: I forced myself therefore, and offered a burnt offering. [made...: Heb. intreated the face]
Contradiction with 2 Chronicles 26:16-19
2 Chronicles 26:16-19 tells how King Uzziah is struck with leprosy for burning incense in the temple, contradicting the idea that anyone could approach God with incense as implied in Numbers 16:6.
2 Chronicles 26:16-19: But when he was strong, his heart was lifted up to [his] destruction: for he transgressed against the LORD his God, and went into the temple of the LORD to burn incense upon the altar of incense.