What is the ruling on using the mosque's personal items, such as a hammer, and is it permissible for someone performing I'tikaf to use the mosque's oil for cooking and heating?

It is not permissible to use mosque tools except for the purpose for which they were endowed. If the mosque imam receives a salary, he may benefit from them as is customary for the general public. If he does not receive a salary, he may benefit to the extent of a fair wage for his services.

It is not permissible to transfer old mosque equipment to another mosque; rather, it must be preserved for the mosque's needs. It is absolutely forbidden to use the mosque's mats and carpets for purposes other than spreading them within the mosque.

Water designated for drinking (sabil) is not permissible for performing ablution (wudu). However, water provided for general use (sabil for general benefit) may be used for wudu, washing clothes, and similar purposes.