G‑d instructed Moses regarding the prohibition for a priest to render himself ritually defiled by touching a human corpse. The exceptions are his close relatives – his parents, siblings, children, and wife – and a corpse that no one else is available to bury.
Not Shirking Responsibility
וְעַל כָּל נַפְשֹׁת מֵת לֹא יָבֹא: (ויקרא כא:יא)
[G‑d told Moses that a high priest] may not ritually defile himself by touching a corpse [unless there is no one else to bury it]. Leviticus 21:11

The high priest’s obligation to ritually defile himself in order to bury an unattended corpse applies even in the unlikely event that such a situation presents itself while he is performing the sacrificial rites of Yom Kippur in the Holy of Holies. If there is no one else who can bury this corpse, the high priest must leave the most sacred part of the Tabernacle on the holiest day of the year in order to do so. This teaches us, firstly, that taking care of our fellow Jews’ crucial needs takes precedence over tending to our own spiritual tasks.

Secondly, we sometimes encounter people who may be considered, figuratively speaking, “unattended, lifeless bodies” – i.e., people who pay no attention to the spiritual side of life and who have no one else to guide them in this regard. In such cases, we must seize the opportunity to assist them, reminding ourselves that even the high priest is required to disregard his most exalted responsibilities on the holy day of Yom Kippur in order to bury an unattended corpse. We, in contrast, have both the obligation and privilege of not merely attending to a “lifeless” person – but of reviving him!1