Here we arrive at the correction this principle quietly administers to a common habit: the habit of ranking acts of worship on a fixed ladder, as though the ladder never moved. Is dhikr superior or recitation? Is recitation superior or nafl salah? Is nafl salah superior or service to people? Asked in the abstract, these questions have answers in the books, and the scholars have discussed them. But asked in the abstract is precisely the problem, because no believer ever worships in the abstract. He worships at Fajr on a Tuesday, with a mother in the next room and an instalment due on Friday.