ViewpointHow occurrence is framedCompatible particle
General classSome occurrence is customaryIdha may fit
Specific subtypeA narrowly specified event is rareIn may fit
Hypothetical scenarioOccurrence is not assertedIn for rhetorical purposes
Rain may be common in a region while severe hail is uncommon. A broad category and a narrow subtype naturally invite different ways of presenting expectation.
This analogy explains the logic of the distinction; it is not intended as an independent exegesis of any Qur’anic phrase.