Valmiki Ramayana Aranya Kanda Sarga 16 Shloka 6
Original Shlokaनवाग्रयणपूजाभिरभ्यर्च्य पितृदेवताः। कृताग्रयणकाः काले सन्तो विगतकल्मषाः।।3.16.6।।
1 source checked for this shloka
सन्तः pious men, नवाग्रयणपूजाभिः with offering of libations of the first crop at Agnistoma sacrifices, पितृदेवताः manes अभ्यर्च्य after worshipping, काले at the proper time, कृताग्रयणकाः the sages who have conducted sacrifice with oblation, विगतकल्मषाः rid of their sins.
Pious men offer their libations of the first crop at Agnistoma sacrifice and thereby please their manes and get rid of their sins.