All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
The statement of a person: "Whenever I marry I will divorce", is not a vow but it is a divorce conditioned on him marrying a woman.
The Muslim jurists have different opinions concerning the one who says: "Any woman whom I will marry is divorced". The predominant opinion is that of the majority of the scholars who are of the opinion that it is not considered a divorce. This is the opinion adopted by Imaams Maalik, Ash-Shaafi’ee and the Hanbali scholars .
However, Imaam Maalik is of the opinion that if he pinpoints a specific woman then she will be divorced.
The basis for those who say that such divorce is not effective is the narration in which the Prophet said: "Divorce is not valid in what one does not possess" (i.e. if the marriage never took place). [Abu Daawood, At-Tirmithi and Ibn Maajah]
If this is the case when one is certain that he uttered those words, then it is more applicable to one who doubts uttering such words. If he doubts, then in principle he did not say them unless there is evidence which proves otherwise.
Finally, a Muslim should avoid uttering the words of divorce in any case since it is a very serious matter. For more benefit please refer to Fatwa 82916.