Skandapurana 5.223.41

5.223.41

akṣayyasalilaṃ deyaṃ ṣaṣṭhyā caiva tataḥ param ..
pavitrāṇi samādāya ūrdhvaṃ svadheti kīrtayet..
astu svadheti tairukte piṃḍopari parikṣipet .. 41 ..

Inexhaustible water is to be given, and then with the sixth [case]; / taking the purifying blades of grass, he should proclaim upwards, 'svadhā!' / When it is said by them, 'Let there be svadhā,' he should throw [them] onto the piṇḍas.