All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
The waiting period during which a woman may be divorced, according to the Sunnah, starts with her purity from the menses, provided that her husband had sexual intercourse with her during the period of her purity from menses prior to divorcing her.
If a husband has sexual intercourse with his wife when she becomes pure and then decides to divorce her, then he must wait until she menstruates once and becomes pure (from this menses) or becomes pregnant, and after that he can divorces her if he wishes.
The husband who wants to divorce his wife is not prevented from touching his wife with desire and lust, but if he has sexual intercourse with her, then it becomes forbidden for him to divorce her until she menstruates and then becomes pure.
Allah knows best.