If a man strikes his wife and she utters a word of disbelief (kufr), is the marriage contract dissolved? And if it is dissolved, is it permissible to take the wife back? And does the woman have an iddah (waiting period) in this case, or must a new contract be performed?

The husband is advised not to strike his wife except within the limits prescribed by Islamic law, if she is disobedient (nashiz) and neither admonition nor shunning in bed has been effective. In such a case, it is permissible to strike her a non-injurious blow if benefit is expected from it, in accordance with the Almighty's saying: "As for those [wives] from whom you fear defiance, admonish them, and abandon them in bed, and strike them. But if they obey you, do not seek a way against them." As for one of the spouses uttering a word of disbelief, this is a cause for annulment of the marriage if they are ruled to be in a state of disbelief after the conditions are met and impediments are absent, and the matter is referred to the Sharia (definition) judge. If the woman has not been entered upon, separation occurs immediately at the time of apostasy, and she cannot return except after a new marriage contract and repentance. As for the woman who has been entered upon, the preponderant opinion is that separation does not occur until the expiry of the waiting period (iddah (definition)).