After Maghrib Fardh Salaah at the Musjid it has become a common practice for the lmaams to stand up and quote a Hadeeth and sometimes give a brief exp

Answer

It is not permissible to engage in a bayaan immediately after the Fardh Salaat of Maghrib or of any Salaat. This is a new bid'ah introduced by those who have been deceived by Iblees. This type of deception is termed Talbeesul Iblees (the deception of Iblees). He misleads with acts which he portrays with Deeni hues.