What is the ruling on an oath of divorce conditioned upon a stipulation, which occurred due to lying to conceal a girl who was engaged, knowing that the oath came about due to the wife's insistence?

If a husband makes his wife's divorce contingent upon something that has already occurred in the past, then the divorce has taken effect. If this pronouncement of divorce does not complete the three pronouncements, the husband may take his wife back during her iddah (waiting period) by saying: "I have taken my wife back," without needing to inform her. It is advisable for the husband, if his wife asks him to swear an oath by divorce, to use dissimulation (tawriyah) and insinuation (ta'ridh) in his oath, intending something other than what his wife understands, and he will not be considered to have broken his oath or committed a sin thereby.