Shivapurana 5.25.6

Śivapurāṇa (complete text) 5.25.6

īśvara uvāca |
satyaṃ te kathayiṣyāmi śāstraṃ sarvottamaṃ priye |
yena śāstreṇa deveśi naraiḥ kālaḥ prabudhyate ||