How long does damage remain on a unit, and does it matter whether the damage is from a commit effect, exhaust effect, or spell?

Ruling: Damage is cleared at the end of combat and end of turn, regardless of the source.

Nuances:

• The timing of when damage is dealt doesn't change when it's cleared (commit effect damage and exhaust effect damage both follow the same clearing rules)
• When damage is cleared at end of combat, it clears from all units everywhere, not just units that participated in that combat