Answer
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- There is nothing wrong in displaying some ads in that room, which you take as mosque.
2- However, we do advise you to do so in the parlor or corridor of the room, away from the place of performing prayer.
In his response to your question, the eminent Muslim scholar, Sheikh `Abdel Khaliq Hasan Ash-Shareef, the renowned Da`iyah, states:
We should differentiate between the mosque and the mere place of performing prayer. A mosque is any place dedicated for prayer; people gather therein specifically for that religious purpose, performing five daily prayers.
This is completely different from an ordinary place used by people for prayer, as well as for other issues. This cannot be called a mosque in the full sense of the word, and it is governed by a ruling different from that of the mosque.
Reflecting on the special case which you referred to in your question, we can say that there is nothing wrong in displaying some ads in that room, which you take as mosque. However, we do advise you to do so in the parlor or corridor of the room, away from the place of performing prayer.
Almighty Allah knows best.
Editor’s note: This fatwa is from Ask the Scholar’s archive and was originally published at an earlier date.