Exodus 28:43

And they shall be upon Aaron, and upon his sons, when they come in unto the tabernacle of the congregation, or when they come near unto the altar to minister in the holy place; that they bear not iniquity, and die: it shall be a statute for ever unto him and his seed after him.

That they bear not iniquity, and die. To bear iniquity, 'is a common Scripture phrase, equivalent to suffer the punishment due to sin,' frequently coupled with the synonymous expressions of 'being cut off from the people,' and 'dying' (cf. Leviticus 19:8).