Skanda Purana 16.261.3

16.261.3

vaiśākhe śuklapakṣe tu tṛtīyāyāṃ ca bhāmini ..
snātvā tu tarpayedbhaktyā tiladarbhajalaiḥ priye ..
śrāddhaṃ kṛtaṃ bhavettena gaṃgāyāṃ nātra saṃśayaḥ .. 3 ..

In the month of Vaiśākha, on the third day of the bright fortnight, O passionate woman, / having bathed and offered libations with devotion using water, sesame seeds, and darbha grass, O beloved, / by him a śrāddha has been performed at the Gaṅgā, without doubt.