Śrāddha-kalpa: Amarakantaka–Tīrtha-Māhātmya and Akṣaya Pitṛ-Tarpaṇa
उक्तमेवाक्षयं श्राद्धं धर्मराजनिषेवितम् / श्राद्धं दत्तममावास्यां विधिना च यथाक्रमम्
uktamevākṣayaṃ śrāddhaṃ dharmarājaniṣevitam / śrāddhaṃ dattamamāvāsyāṃ vidhinā ca yathākramam
The imperishable śrāddha is said to be that observed by Dharmarāja: the śrāddha offered on the new-moon day (amāvasyā), duly and in proper order.