Exodus 30:21
they shall wash their hands and their feet, so that they do not die. And it shall be a statute forever to them, to him and to his seed throughout their generations.
Exodus 28:43
And they shall be upon Aaron, and upon his sons, when they come in to the tabernacle of the congregation, or when they come near the altar to minister in the holy place; so that they do not bear iniquity, and die. It shall be a statute forever to him and his seed after him.
Exodus 27:21
in the tabernacle of the congregation, outside the veil which is before the testimony. Aaron and his sons shall order it from evening to morning before Jehovah. It shall be a statute forever to their generations on behalf of the sons of Israel.