Leviticus 10:5-6

⁵So they came and took them, in their coats, outside the tent-circle, as Moses had said.

⁶And Moses said to Aaron and to Eleazar and Ithamar, his sons, Do not let your hair be loose, and give no signs of grief; so that death may not overtake you, and his wrath come on all the people; but let there be weeping among your brothers and all the house of Israel for this burning of the Lord's fire.