{ Oh you who have believed, whenever you enter into marital relations with believing women, but then divorce them before you have touched them, you need not assume any waiting period [‘iddah] for them; so make them content with provisions and dismiss them duly and graciously } Al-ahzab 49

In this noble verse are numerous rulings, among them taking “marital relations” [nikah] to mean the marriage contract alone; there is no verse in the Qur’an more explicit in this regard than this one. There is disagreement regarding nikah, split among three opinions: is it truly just the marriage contract, the intercourse, or both? The usage in the Qur’an is that it indeed refers to the contract as well as the intercourse following it, except in this verse here. It is used in regards to the marital contract alone in His word { Whenever you enter into marital relations [nikah] with believing women, but then divorce them before you have touched them } ; and here is the indication that it is permissible to divorce a woman before entering her.
And His word { Believing women } puts forth what is typically the case, although it is agreed that there is no difference in ruling between a believing woman and a woman of the Book regarding this. Ibn ‘Abbas, Sa’id ibn Al-Musayyib, Hasan Al-Basri, ‘Ali ibn Al-Husain Zain Al-‘Abidin, as well as a group of those before them, inferred from this verse that divorce may not occur except if nikah preceeds it, since Allah Most High said { Whenever you enter into marital relations with believing women, but then divorce them } ; divorce follows nikah, and this is evidence that it is not valid nor may it occur before it. This is the doctrine held by Al-Shafi’i, Ahmad ibn Hanbal, and a sizeable party of those preceding them, may Allah Most High have mercy on them.
… and His word { You need not assume any waiting period [‘iddah] for them } : this is a decree on which scholars agree – that a woman, if she is divorced before she is entered, is not obligated to an ‘iddah, and she may immediately go and marry whoever she wishes. There are no limitations, except in the case of a woman whose husband has passed away, in which case she is to observe four months and ten days for him, even if he had not entered her; this is also universally agreed.