What is the ruling regarding someone whose heart is stirred by the occurrence of divorce due to an ambiguous pronouncement, who cannot recall the exact words he said to his wife, but believes it was either an apparent metonymy or an explicit phrase, and it was uttered spontaneously without thought?

As long as this brother is not certain about the exact wording he uttered, and whether it was an indirect expression (kinaya) or an explicit statement (sareeh), the matter remains according to the original principle, which is the wife's retention in his marital bond. She is not divorced unless he is certain about what he said to her. If it was an indirect expression, no divorce occurs as long as he did not intend to divorce her. If the "heart's movement" mentioned in the question refers to the heart's resolve that the intent of this wording was to effect divorce, then this is precisely the intention (niyyah (definition)). However, if something else was intended, then no divorce occurs merely by an indirect expression, as it is not an intention. If you are unsure whether the "movement" that occurred constitutes an intention or not, then the original principle is the continuation of the marital bond. Scholars have explicitly stated that if someone doubts whether he has divorced his wife or not, the marital bond remains. Some have categorized this under the rule: "Doubt concerning a preventative factor does not cause harm." All of this applies if you are certain that what you uttered was an indirect expression, or if you are doubtful whether it was an indirect expression or an explicit statement. However, if you are certain that it was an explicit statement, then you have divorced, based on the Prophet's (peace and blessings be upon him) saying: "There are three matters whose seriousness is serious and whose jesting is serious: marriage, divorce, and رجعة (revocation of divorce)." This brother should, therefore, cut off these obsessive doubts in this matter and build upon certainty. If his heart is not at ease, he should consult one of the scholars or Sharia (definition) judges to discuss it with them.