He was asked—may Allah have mercy on him:

A judge who also serves as a preacher was assigned a stipend from a mosque’s surplus revenue. For two years he received nothing because there was no surplus. Then the revenue increased in the third year. May he take three years’ worth of stipends from that revenue?

He answered:

If the third year’s revenue has lawful uses designated by a valid stipulation, it must be spent on those purposes, and the judge may not take it. But if it has no designated use at all, and the ruler deems it appropriate to allocate it to the judge as compensation for what he missed in the past, that is permissible. And Allah knows best.