What is the ruling on someone who swore an oath by Allah not to install a landline phone in his house, then went back on that, and what is the ruling on his marriage?

If a person swears by Allah concerning a matter and then wishes to retract it for a valid reason, there is no impediment to doing so, and he must offer expiation for breaking an oath (kaffarat yameen). This is based on the Almighty's saying: (And do not make [your oath by] Allah an obstacle against your being righteous and fearing Allah and making peace among people.) [Al-Baqarah:224], and on the Prophet's (peace be upon him) saying: "If you take an oath and then find something else better than it, then do that which is better and offer expiation for your oath." The expiation for an oath is feeding ten poor people, or clothing them, or freeing a slave. If one cannot find [any of these], then it is fasting for three days. However, if the oath was by divorce, it is considered a conditional divorce that takes effect upon the fulfillment of the condition.