Charging a fee for delivering an Islamic speech

If the Aalim charges a fee for delivering a speech, then it is permissible as this is a form of educating people, though not charging is better and more rewarding. Nevertheless, in the case where the Aalim charges, he should not charge a fee when giving a speech in the musjid as the Fuqaha have mentioned that it is makrooh to teach deen in the musjid and take a salary. This will amount to using the musjid as a place for doing business and earning wealth.

And Allah Ta'ala (الله تعالى) knows best.