Matsyapurana 16.23

16.23

agnimānnirvapetpitryaṃ caruṃ ca samamuṣṭibhiḥ
pitṛbhyo nirvapāmīti sarvaṃ dakṣiṇato nyaset //

Srâddha should be performed near a cow-pen or by a pool of water, after plastering the floor, which should be sloping towards the south, with cowdung. One who consecrates and maintains the sacred fire, should cook rice (charu), and after offering with equal handfuls and saying ("I am offering to the Piṭris)," should place everything toward the south.--22-23.