He—may Allah have mercy on him—was asked:

If someone rents a house for his own enjoyment, may he let it out?

He replied:

If someone hires a service for a prohibited act, such as singing, fornication, false testimony, or killing someone whose life is protected, that hiring is prohibited.

Likewise, he may not hire out his services to perform something already obligatory upon him—for example, giving testimony concerning a right, issuing a fatwa on a question, adjudicating a dispute, or undertaking jihad—when that duty has become an individual obligation upon him. Taking payment for this is impermissible.

If the hiring is for an act particular to those engaged in devotional duties—such as teaching the Quran or religious knowledge, leading prayer, giving the call to prayer, performing Hajj on another’s behalf, or undertaking jihad that is not individually obligatory—then scholars differ concerning it.

If the hiring is for work such as tailoring, carpentry, or construction, it is permissible by agreement.