Shivapurana 7.2.20.18

Śivapurāṇa (complete text) 7.2.20.18

śiṣyān parīkṣya yatnena śivaśāstroktalakṣaṇaiḥ |
saṃskṛtya ca śivajñānaṃ tebhyo dadyācca deśikaḥ ||