Sometimes, when people celebrate weddings, whether in wedding halls, hotels, or elsewhere, the family of one of the spouses ask a seeker of religious knowledge to deliver a Khutbah (sermon) as a reminder and advice to the attendants.
The Khutbah is often about marriage-related issues, such as exaggeration in Mahr (mandatory gift to a bride from her groom), extravagance in Walimah (wedding dinner), and prohibited acts committed in wedding ceremonies, such as Taswir (photography), free intermixing (of men and women), singing, and the like. Some people object to this on the pretext that nothing was related in this regard. What is the ruling on this matter? May Allah reward you best.
(Part No. 19; Page No. 107)
There is no harm in delivering a useful Khutbah to the attendants in a wedding ceremony, in order to enjoin good and forbid evil. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.