Is it permissible for the supervisor of an endowment (waqf) to take 10% of its annual income, such that if the income is one million riyals, his share would be 100,000 riyals, or is this amount excessive?

If the remuneration received by the Waqf administrator was small in the past and has become large now, he should not consider all of it lawful for his work, because his work might be minimal, such as supervision, leasing, collecting rent, and disbursing it. He should limit himself to the amount of remuneration that others who perform the same tasks would receive.