Kōan collections — the Blue Cliff Record, the Gateless Gate — are anthologies of encounter dialogues between teachers and students, each with commentary and verse. They are not riddles with clever answers: the collections are used in formal practice where a student sits with one case for months or years and demonstrates their understanding to a teacher in private interview, and the demonstration is usually not verbal. Reading them casually, which is how most Westerners meet them, is a category error the tradition finds amusing rather than offensive.