If a man divorces in a state of psychological agitation a thousand times, then declares ẓihār

Answer—and Allah is the One who grants success: Pronouncing a thousand divorces upon one’s wife is a sin and a transgression of the bounds Allah has set for His servants in His Noble Book. He must repent and seek forgiveness. His wife is deemed divorced one pronouncement, and he may take her back if this does not complete three. If this pronouncement completes three—i.e., he had previously divorced her twice—then he has no right of return to her, and she is not lawful for him until she marries another husband.
As for the ẓihār after the divorce, it does not take effect and carries no consequence, as the scholars of the madhhab have said, and there is no expiation due for it. One may adduce as evidence His saying, Exalted is He: "Those among you who declare their wives unlawful to them [by ẓihār] …" [Al-Mujādilah:2], and His saying: "And He has not made your wives whom you declare [by ẓihār] to be like your mothers your [actual] mothers." [Al-Aḥzāb:4]. A divorced woman is not a “wife.”
If it be said: A revocably divorced woman (in ʿiddah) has the rulings of a wife; thus it is forbidden for the divorcer to marry his wife’s sister or a fifth wife, and maintenance is due to her, and the like.
We say: She is not called a “wife” in the law; she is called a “divorcee.” Maintenance during the waiting period is due by proof, such as His saying: "And if they are pregnant, then spend on them until they deliver their burden." [At-Ṭalāq:6]—not because she is a wife.
The prohibition of marrying the sister and a fifth wife is also by proof, namely: that Allah, Glorified, has granted the husband the right to take back his wife so long as she is in the waiting period of a revocable divorce. He said: "And their husbands have more right to take them back in that [period]." [Al-Baqarah:228], and He said: "Perhaps Allah will bring about after that a [different] matter." [At-Ṭalāq:1].
From this we know that it is not permissible for the husband to marry the sister or a fifth wife, because that would nullify the revocation which the Qurʾān has affirmed. If the sister or the fifth were permissible, revocation would be nullified; yet it is known—as the Qurʾān indicates—that revocation is the husband’s right so long as the revocably divorced woman remains in her waiting period. Therefore the sister and the fifth are forbidden due to their contravention of revocation, not because the divorcee is a “wife.”
Hence they said that a fifth wife is permissible for one whose wife has been divorced three times—and likewise the sister.
Moreover, divorce is the undoing of the knot of marriage; thus Allah called it “release.” Allah legislated and obligated the waiting period (ʿiddah) for great benefits to people, among them what He mentioned: "Perhaps Allah will bring about after that a [different] matter." [At-Ṭalāq:1]. A husband may regret the divorce, so Allah granted him time and choice—He set a term for him to review his soul and consider his affairs; perhaps the divorce issued in anger, over a trivial matter, or by weak judgment.
Among the benefits is preserving lineages from mixing. If a divorcee were to remarry immediately after divorce, lineages would be confused, due to the possibility of conception from the first husband. For this reason Allah forbade contracting marriage with the divorcee until she completes her waiting period: "And do not resolve on the tie of marriage until the decree reaches its term." [Al-Baqarah:235]. Thus the divorcee during her waiting period is not a wife; rather, she is released from the husband’s bond and set free from his tie. The link that remains after divorce is only for the benefits mentioned—not because she is still a wife.
Maintenance is due to her from the husband during the waiting period because the waiting period is imposed upon her for interests that pertain to the husband—namely, preserving his lineage from being lost and awaiting his choice to take her back.
The proof that the waiting period was legislated to prevent the mixing of lineages is His saying, Exalted is He, regarding a woman divorced before consummation: "Then you divorced them before you had touched them—then there is not for you any waiting period to count against them." [Al-Aḥzāb:49].
Source : Min Thimār al-ʿIlm wa al-Ḥikmah vol.1