Not mourning for the death of one’s family might seem unnatural, but it stands to reason that when the priests have been committed to the Lord, they are responsible to align themselves with him even when members of their family face his judgment. Since the death of Nadab and Abihu resulted from their disobedience to the Lord’s commands, mourning them would imply allegiance to Nadab and Abihu. Wenham suggests, “Had they joined in the traditional customs of tearing their clothes, they might have been tempted in their grief to blame God for their brothers' death.”1
6 Moïse dit à Aaron, à Eléazar et à Ithamar, fils d'Aaron: Vous ne découvrirez point vos têtes, et vous ne déchirerez point vos vêtements, de peur que vous ne mouriez, et que l'Eternel ne s'irrite contre toute l'assemblée. Laissez vos frères, toute la maison d'Israël, pleurer sur l'embrasement que l'Eternel a allumé.