Book of Divorce
It is permissible for one who is liable to the obligations of Islam and is free to act voluntary even if divorce was due to mere jest.
It is permissible to divorce in the case of woman who is in the state of purity wherein her husband did not have sexual intercourse with her. It is unlawful to divorce her in the period (of menses), but he is allowed to do so during pregnancy. However, it is forbidden to undertake divorce in a manner other than the prescribed above.
Divorce happens merely by saying any indirect word with the intention to divorce.
The divorce also happens whenever the wife chooses to separate herself but, with the consent of the husband. If the husband authorizes someone else to undertake divorce instead of him, divorce will still be just as valid.
Divorce is not valid in the case of Tahreem (i.e. declaring your wife as unlawful to you).
The husband is more deserving of his wife in her Iddah of divorce (i.e. period of post-divorce), and he may retrieve her whenever he wants if the divorce is one that allows retrieval. Yet, she becomes illegal for him after the third divorce until she marries another man.
 Hasan: Narrated Abu Hurairah: The Prophet (ﷺ) said: “There are three things which, whether undertaken seriously or in jest, are treated as serious: Marriage, divorce and taking back a wife (after a divorce which is not final).” Recorded in Sunan Abu Dawud. Graded Hasan by sheikh albani in Irwaa al-Ghaleel, no. 1826
 Sahih: Anas bin Sirin reported: I asked Ibn ‘Umar about the woman whom he had divorced. He said: I divorced her while she was in the state of menses. It was mentioned to ‘Umar and he then made a mention of that to Allah’s Messenger (ﷺ), whereupon he said: Command him to take her back and when the period of menses is over, then (he may divorce her in the state of her purity. He (Ibn Umar) said: So I took her back, then divorced her in her purity. I (the narrator) said: Did you count that divorce which you pronounced in the state of menses? He said: Why should I not have counted that? Was I helpless or foolish? Recorded in Sahih Muslim, 1471
 That is it is forbidden to divorce a woman when she is in a period of menses or in a state of purity in which he had sexual intercourse with her.
 Sahih: Ibn Umar when he divorced his wife while she was having menses, the Prophet (ﷺ) said: “It is one divorce.” Recorded by Ad-Daraqutni 4/10. Graded Sahih by sheikh albani in Irwaa al-Ghaleel, 7/134.
 It means that if the husband elects someone else, who is liable to the obligation of Islam, to divorce his wife instead of him divorce happens.
 Qur’an: Allah says: “…And their husbands have more right to take them back in this [period] if they want reconciliation…” Surah Baqarah: 228
 Qur’an: Allah says: “And if he has divorced her [for the third time], then she is not lawful to him afterward until [after] she marries a husband other than him….” Surah Baqarah: 230