And Moses said unto Aaron, and unto Eleazar and unto Ithamar, his sons, Uncover not your heads, neither rend your clothes; lest ye die, and lest wrath come upon all the people: but let your brethren, the whole house of Israel, bewail the burning which the LORD hath kindled. Uncover not your heads, etc. - They were to use no sign of grief or mourning,
1. Because those who were employed in the service of the sanctuary should avoid every thing that might incapacitate them for that service; and,
2. Because the crime of their brethren was so highly provoking to God, and so fully merited the punishment which he had inflicted, that their mourning might be considered as accusing the Divine justice of undue severity.