VasDhS, 23, 19.1 jīvann ātmatyāgī kṛcchraṃ dvādaśarātraṃ caret trirātraṃ hy upavasen nityaṃ snigdhena vāsasā prāṇān ātmani cāyamya triḥ paṭhed aghamarṣaṇam iti //

VasDhS, 25, 13.2 triḥ paṭhed āyataprāṇaḥ prāṇāyāmaḥ sa ucyate /