What is the ruling regarding a husband saying to his wife: "Enough" (khalas), perhaps followed by "I am tired of this" or "I am done with these things," with the possibility of him having an intention of separation, two and a half years after the incident, and without his prior knowledge of allusive divorce (طلاق الكناية) or its rulings?

Divorce from a legally competent and conscious husband does not occur except with an explicit pronouncement, or an implicit one accompanied by the intention to effect it. It does not occur with doubt or hesitation regarding its occurrence or conditions. What is mentioned in the question does not result in divorce; rather, these are [mere] whisperings that must be ignored.