Skandapurana 5.193.30

5.193.30

nāḍī ṣaṣṭipalā proktā tāsāṃ ṣaṣṭyā dinaṃ niśā ..
niśvāsocchvasitānāṃ ca parisaṃkhyā na vidyate ..
sadāśivasamutthānāmetasmātso'kṣayaḥ smṛtaḥ .. 6.194.30 ..

A nāḍī is declared to be sixty palas; by sixty of them, day and night [are formed]. / And of the inhalations and exhalations arising from Sadāśiva / there is no reckoning; therefore he is remembered as imperishable.