Skandapurana 5.220.57

5.220.57

yaścaitatkīrtayecchrāddhe kriyamāṇe nṛpottama ..
viprāṇāṃ bhokttukāmānāṃ tacchrāddhaṃ tvakṣayaṃ bhavet ..57..

And whoever recites this while a śrāddha is being performed, O best of kings, / before the brahmins who wish to eat, that śrāddha of his becomes imperishable.