Why translate 'X etadahosi' as 'the thought occurred to X'?
I'm not an expert (please consider this instead as an "exercise for the student" for someone to correct).

When it's used in a phrase like, "bhikkhūnaṃ etadahosi", isn't "bhikkhus" there in the plural genitive or plural dative case? Anyway, not nominative. So wouldn't you translate that as "of the bhikkhus", or, "to the bhikkhus"?

You say you translate 'etadahosi' literally as 'was thus' ... could it mean instead, "this was"?

Anyway, given that "bhikkhus" isn't nominative, maybe the most literal translation is, "this was, to the bhikkhus" ... or in other words, "this (thought or statement) occurred, to the bhikkhus".

If I look at other instances of etadahosi I see they too are preceded by a noun with the naṃ or ssa case endings.



Also it sometimes is translated as "they thought".