Not only were there ritual obligations in the Tabernacle and Temple, but ethical duties, pedagogic tasks and spiritual obligations.
For instance, “Aaron shall bear the judgment of the Children of Israel on his heart before the Lord” (Ex. 28:30).
One of the commentators says that this shows that Aaron was like the people’s heart. Whatever situation they were in, he felt it in his heart before there was any outward manifestation.
It’s not an easy burden to be a leader, because all leadership – of whatever kind – must take its cue from this aspect of Aaron. The leader has to feel what is going on within the people, and has to know what is going to happen before it happens.
The moment that the heart of the leader loses this instinct, it is time to step down and retire from office.