What is the ruling on painting the mosque, restoring some of its parts, and covering zinc iron with fabric or gypsum for decoration? Is it permissible to supplicate against a business partner who lied, embezzled money, and invested it in an unagreed-upon project?

It is permissible to paint the mosque and cover its walls when needed or for beautification, as long as it does not involve extravagance, boastfulness, or distraction for the worshipers. However, it is forbidden to adorn it with gold and silver, and it is disliked to adorn it with engravings, dyes, writing, and anything that distracts the worshiper from their prayer. It is obligatory to remove such things if they are from endowed property (waqf). It is permissible to plaster mosques, meaning to whiten them.

Regarding adorning mosques with gold and silver and hanging their lamps, there is a detailed discussion between prohibition and permissibility. As for covering mosques with cloths, there is no harm in it if it is not silk. Some scholars have held the view that it is permissible to cover the Kaaba with silk and have extended this ruling to other mosques.

Restoring mosques to repair or strengthen them is considered part of the legally commanded maintenance of mosques, and it is a collective obligation (fard kifaya).

The restoration of mosques is divided into three categories: 1. Non-essential restoration: This type of restoration is not needed and is closer to sin, as it involves wasting money without benefit. 2. Needs-based restoration: This type of restoration is needed but not essential, such as stripping tiles. The person who undertakes this will be rewarded for cleaning the mosque. 3. Essential restoration: This type of restoration is necessary, such as repairing cracked walls. This takes the ruling of construction because it is essential.

As for supplicating against the oppressor, it is permissible in Islamic law, based on the Almighty's saying: "Allah does not like the public utterance of evil, except by one who has been wronged. And Allah is Hearing, Knowing." [An-Nisa: 148].