Does a divorce issued by the husband three consecutive times, and then again in front of his wife's father, take effect, knowing that he uttered it during a period of purity in which intercourse occurred, resulting in pregnancy, due to his suspicion about his wife's chastity when she was in seclusion with her foster brother, and then they both affirmed their innocence and swore to it? And can the wife be taken back after she gives birth, and what is the manner of taking her back in this case?

Pronouncing a triple divorce with a single utterance is impermissible, and it is called an innovated (bid'i) divorce due to its contravention of the Sunnah (definition) regarding the number [of pronouncements]. Similarly, divorcing a wife during a period of purity (tuhr) in which he had intercourse with her is an innovation (bid'ah) in terms of timing. As for the occurrence of a triple divorce with a single utterance, it takes effect according to the majority of scholars. Some, however, are of the view that it constitutes a single divorce, which is the position adopted by Sheikh al-Islam Ibn Taymiyyah and Ibn al-Qayyim. Divorce pronounced during a period of purity in which he had intercourse with her is effective by agreement of the four madhhabs. The presence of the wife or her knowledge of the divorce is not a prerequisite.