Can money vowed as charity be used to build a mosque?

Initiating a vow (nadhr) is disliked (makrooh). However, if it is conditional and the condition is met, then fulfilling it becomes obligatory. The interpretation of the vow refers back to the intention of the one who made it, provided the wording can accommodate that intention. If the intention specified charitable causes, then it is not permissible to spend the vow on anything else. If the intention was general, then it includes all good deeds, such as building mosques, sponsoring orphans, and other similar acts. A vow is not to be equated with zakat, which has specific categories of recipients.