What is the waiting period (iddah) for a woman divorced three times? Is it permissible for her to marry immediately after receiving her divorce decree? And can she return to her former husband during the waiting period?

The waiting period (iddah) is obligatory for every divorced woman with whom her husband had consummated the marriage, whether the divorce is revocable or irrevocable, based on the generality of Allah's Almighty saying: "And divorced women remain in waiting for three periods." The iddah becomes obligatory after the third divorce, and the husband is not permitted to take her back. Rather, she becomes unlawful to him until she marries another man with a valid marriage and he divorces her after consummation, based on Allah's Almighty saying: "And if he has divorced her [for the third time], then she is not lawful to him afterward until she marries another husband." The divorced woman is not permitted to marry before the completion of her iddah. The iddah begins from the moment the husband pronounces the divorce, unless the divorce is by a judge's ruling, in which case the iddah begins from the time the ruling is issued.