Chapter on Sunnah-Compliant Divorce and the Innovative (bidʿah) Forms
The Sunnah for a man who intends to divorce his wife is to pronounce a single divorce during a period of purity in which he has not had intercourse with her.
If he pronounces three divorces—even in one utterance—it is unlawful; likewise, if he divorces her while she is menstruating or during a purity in which he has had intercourse with her, even with only one declaration, the divorce is considered bidʿī (innovative), is therefore sinful, yet it still takes legal effect.
No ruling of Sunnah or bidʿah applies to divorcing a woman with whom the marriage has not been consummated, a minor, a post-menopausal woman, or a pregnant woman.
Divorce and khulʿ (redemptive divorce) are permissible at her request even during a time that would otherwise be deemed bidʿah.