What is the ruling on taking payment for performing services for the mosque? And what are the references that have addressed this issue?

Mosques fall under the rulings of Waqf (endowment). The administrator of the Waqf is entitled to a salary if he is a manager overseeing its affairs. As for the muezzin, imam, and worker, scholars have differed regarding the permissibility of their taking a salary. The preponderant opinion is that it is permissible if the individual is poor and in need, and if the mosque requires his full-time dedication.