The notables of Ottoman Egypt were in part a rentier class: one which collected "rents" by holding (and exchanging and inheriting) tax farms, waqf-funded offices, and soldiers' wages and rations. Often the imperial government's efforts to reassert control over these offices and revenues took the form of cutting off the payment of soldiers' wages to "children and dependents." Yet a threat to rescind some of these "rents" was understood as a threat to the entire rentier class, and evoked a vigorous response from the 'ulamā'. Their juridical arguments in defense of the status quo made use of the legal concept of irsād (sultanic waqf). Irsāds, which began to be established in the sixth/twelfth century, were endowments of state revenue land by the rulers in support of religious and public works. This essay, based on literary and legal sources, manuscript and printed, traces the history of the concept of irsād from its origin to the Ottoman era, and shows how, in Ottoman Egypt, it was used to justify the political and economic position of the notables.