Brahma-vidyā through Yoga: Restraint, Pranava Japa, and Samādhi leading to Mokṣa
षट्त्रिंशन्मात्रकः श्रेष्ठश्चतुर्विंशतिमात्रकः / मध्यो द्वादशमात्रस्तु ओङ्कारं सततं जपेत्
ṣaṭtriṃśanmātrakaḥ śreṣṭhaścaturviṃśatimātrakaḥ / madhyo dvādaśamātrastu oṅkāraṃ satataṃ japet
Oṁ uttered with thirty-six mātrās is the best; that with twenty-four mātrās is also excellent; the medium measure is twelve mātrās. Therefore one should continually repeat the Oṁkāra.
Lord Vishnu (in instruction to Garuda/Vainateya)
Concept: Pranava-japa with regulated mātrā (duration) refines attention and steadies mind toward liberation.
Vedantic Theme: Oṁ as śabda-brahman leading to para-brahman; upāsanā as a support for nididhyāsana.
Application: Practice Oṁ-japa daily with a chosen mātrā-count (12/24/36) suited to capacity; keep rhythm steady and attention on resonance rather than volume.
Primary Rasa: shanta
Related Themes: Garuda Purana 1.235.25 (Pranava knowledge; Viṣṇu-mantra; Gāyatrī); Garuda Purana 1.235.26-28 (pratyāhāra, dhāraṇā with prāṇāyāma)
This verse presents Oṁ as a constant japa-practice and even specifies graded mātrā-lengths, implying that disciplined, measured recitation of Oṁ is a central, repeatable sādhana.
They indicate the time-length of the utterance of Oṁ in mantra-recitation; 12 mātrās is described as the medium measure, 24 as a higher measure, and 36 as the best (most refined/extended) form of chanting.
Maintain a steady daily practice of Oṁ repetition, gradually training attention and breath to chant it in a measured, unhurried way (starting with a comfortable length and moving toward more sustained recitation).