Does a divorce become effective if the husband conditioned it with the statement: "It is a divorce oath from me that you did not say these words," given that the wife is certain she said them, and they differ on the specific time period intended by the oath?

If a husband swears that his wife did not tell him something, and he intended a specific time during which that did not occur, then he does not break his oath, because in oaths, what matters is the intention of the swearer. Divorce does not take effect based on doubt about its occurrence, or doubt about the condition upon which divorce was made contingent. Assuming the wife is certain that the matter occurred at the time the husband intended, the preponderant opinion is that he does not break his oath if he believed himself to be truthful. It must be noted that the permissible oath is swearing by Allah Almighty, whereas swearing by divorce is among the oaths of the dissolute.