The World Federation One Stop Fiqh

Ruling 2524

If a man has sexual intercourse with a woman who is clear of ḥayḍ  and nifās and he then separates from her – for example, he goes on a journey – then, in the event that he wishes to divorce her while he is away but is unable to find out about her state, he must wait long enough for her to experience ḥayḍ once more and become clear of it. And the obligatory precaution is that the period [he waits] must not be less than one month. Furthermore, if he divorces her, having observed what was said, and it then becomes known that the divorce took place during the first period of her being clear, there is no problem.