Madhvacharya's Dvaita Vedanta and translation of Sarvamoola containing Bhagavad Gita, Upanishads, and Brahmasutra.

Tantrasāra Saṅgraha

Tantra Sāra 1.033

आदिवर्णत्रयं नाभिहृच्छिरस्सु यथाक्रमम्। न्यसनीयं च तद्वर्णदेवताध्यानपूर्वकम् ॥३३॥

ādivarṇatrayaṁ nābhihr̥cchirassu yathākramam। nyasanīyaṁ ca tadvarṇadēvatādhyānapūrvakam ॥33॥

The three primal syllables (Ā, Ū, Ma) must be placed in proper order at the navel, the heart, and the head, by meditating on the gods of those respective syllables.

Note:
"Nyāsa" i.e. "to place", is the process of installing the form of the lord at various body parts before starting the meditation. It is performed for protection and purification. As per tradition, one should touch the three body parts chanting below mantras as part of Nyāsa:

"Ām Vishwāya Namaha" - touch the navel, meditating on Universal form of the lord.
"Ūm Taijasāya Namaha" - touch the heart, meditating on the energy form of the lord.
"Mam Prajnāya Namaha" - touch the head, meditating on the omniscient form of the lord.

बहुचित्रजगद्बहुधाकरणात् परशक्तिरनन्तगुणः परमः ।
सुखरूपममुष्य पदं परमं स्मरतस्तु भविष्यति तत्सततम् ॥
"The one who has created this variegated vast universe with varied forms has infinite power and is of infinite auspicious qualities. He certainly bestows the highest state of bliss to those who meditate on his ever happy essence." -Dwādasha stōtra 4.3

Contact:
enquire@madhva.in