Talking in mosques
Q- Is it permissible to talk about worldly matters inside the masjid and at a time other than the salah?
A – All praise is due to Allah. It is not permissible to use the masajid as places of selling, trading, or other worldly affairs. The masajid were built for the remembrance of Allah, recitation of the Qur’an and offering prayers.
However, it is permissible to speak a little about worldly matters as long as it does not distract the reciters (of the Qur’an) or those praying.
– The Permanent Committee for Islamic Research and Verdicts
Preaching without practicing
Q- If after repeated attempts, a person is not able to apply something that he exhorts others to do, is it still permissible for him to call others to do that action? What if he does so supposing that the person he is calling will be able to apply what he failed to apply himself?
A – When one is inviting others to do a good thing that he himself is not capable of doing, then yes, he should call others to do it. An example of this is if someone calls others to pray late at night while he himself is not able to do so or if someone calls others to give charity, but he himself has no sufficient resources to give charity, then we tell him to go ahead and invite others to give charity. But as for him calling to something that he is capable of doing but doesn’t, then this is foolish in intellect and going astray in religion.
– Sheikh Muhammad Bin Saleh Al-Uthaymeen; Fatawa Islamiyah, vol. 8, pg. 56