Person 1: Yoooo have you read the latest chapter of unOrdinary?!!
Person 2: Yeah omg it was awesome!!
Person 3: Wait shhhh don't spoil I haven't read it yet!
When some resigns or retires from a job, they are on "eternity leave". This can also refer to someone who has passed away, especially someone who worked somewhere for a long time, retired/resigned, then passed away later.
Oh I'm sorry, you didn't know that Kelly is on eternity leave? She resigned and moved to Hawaii!
With regrets I would like to inform you that my boss is officially on eternity leave. I will never see or hear them again. Ever.