Garudapurana 2.26.47

2.26.47

ekenaiva tu pākena śrāddhāni kurute sutaḥ /
ekaṃ tu vikiraṃ kuryātpiṇḍāndadyadbahūnapi /
tīrthe cāparapakṣe vā candrasūryagrahe 'pi vā //

With only one cooking the son performs the śrāddhas; / he should make a single scatter-offering, but give many piṇḍas / at a sacred ford, during the dark fortnight, or during an eclipse of the moon or the sun.