How a Divorcer Can Avert a Conditional Divorce

Answer—and Allah is the One who grants success: If we say that divorce does not fall upon the woman until after the entry—i.e., upon the occurrence of the condition—then averting it may be valid through taḥbīs (a “holding/waqf device”).
But if we say that the divorce has already issued from the husband, and the condition merely restricts its settling upon the woman, then it cannot be averted by taḥbīs.
Yes: reliance should not be placed upon taḥbīs and al-dawr (circular legal stratagems), nor should they be employed. They should not stand as a barrier against the separation Allah—Glorified is He—has legislated when there is need for it, for He—Exalted is He—says: "Then [there must be] retention in kindness or release with good treatment." [Al-Baqarah:229], and "Do not keep them, injuring them, so that you transgress." [Al-Baqarah:231].
Yes: in the Sharḥ it says: “If the waqif (endower) made a waqf upon a condition—such as saying, ‘I dedicate such-and-such if Zayd comes,’ or the like—the apparent view is that such conditions cannot be revoked Ê by wording, but only by an act like sale and the like.” In the marginal notes of the jurist ʿAlī, he made it a point of disagreement between al-Muʾayyad Billāh and al-Qāḍī Zayd: al-Muʾayyad Billāh says he may revoke by act or by speech; al-Qāḍī [Zayd] says by act.
And in al-Azhar: “Whoever dedicates (a waqf) after his death—he has, before his death, the right to revoke it.” And in the Sharah thereon: “The apparent sense of his words implies that he may revoke Ê by act or by speech.”
And they said regarding one who manumits his slave after his death: he may revoke it before his death by act, not by speech.
I say: In this is an indication that it is valid—on the view of al-Muʾayyad Billāh—to avert dispositions suspended upon conditions by act and by speech; and the people of the madhhab are bound to that—since they say that one who dedicates a waqf after death has, before death, the right to revoke by speech and by act.
And in the Amālī of Aḥmad ibn ʿĪsā (peace be upon him): from ʿAlī (peace be upon him), concerning one who says to his wife: “You are thrice divorced if I do not fast on the Day of Sacrifice”—he (peace be upon him) said: “If he fasts it, his wife is not divorced.” And in it: that a man swore by the divorce of his wife if he did not have intercourse with her in the daytime of Ramaḍān; so ʿAlī (peace be upon him) said: “Travel to the Madaʾin, then have intercourse with her in the daytime—thereupon food, drink, and intercourse are lawful for you.”
From these two narrations it may be inferred that retraction by speech is not valid in an oath by divorce or in a divorce by suspension.
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1