Skandapurana 5.214.37

5.214.37

jalenāpi ca yaḥ śrāddhaṃ śākenāpi karoti vāḥ ..
darśasya pitarastṛptiṃ yāṃti pāpaṃ praṇa śyati . 37 ..

And whoever performs a śrāddha on the new moon even with water, or even with vegetables, / their ancestors attain satisfaction, and [their] sin is destroyed.