Skandapurana 16.336.268

16.336.268

pitṝṇāṃ jāyate tṛptistena dvādaśavārṣikī ..
śrotavyaṃ prayatairnityaṃ narairnarakabhīrubhiḥ ..
paṭhitavyaṃ sadā bhaktyā viprāṇāṃ bhuṃjatā puraḥ .. 268 ..

Through this, satisfaction lasting twelve years arises for the ancestors; / it should constantly be heard with self-restraint by men who fear hell; / it should always be recited with devotion before brahmins while they are eating.