Shri Chaitanya Upanishad - Atharva Veda

In the Shri Chaitanya Upanishad-Atharva Veda (11-14), the maha-mantra is glorified:

(11) sa eva mula-mantram japati, harir iti krishna iti rama iti.

“The Supreme Lord (who will appear in Kali-yuga as Lord Gauranga) will chant a mantra consisting of His own names Hari, Krishna, and Rama (i.e. the maha-mantra: Hare Krishna, Hare Krishna, Krishna Krishna Hare Hare, Hare Rama Hare Rama Rama Rama Hare Hare).

(12) harati hridaya-granthim vasana-rupam iti harih. krishih smarane tac ca nas tad-ubhaya-melanam iti krishnah. ramayati sarvam iti rama ananda-rupah. atra shloko bhavati.

“These three seed names of the maha-mantra of the Supreme Lord (Hari, Krishna, and Rama) may be explained in the following way: {1} ‘Hari’ means He who removes (harati) the knot of material desire in the hearts of the living entities; {2} ‘Krishna’ is composed of the two syllables ‘krish’ and ‘na’. 'Krish' means He who attracts the minds of all living entities, and ‘na’ means the supreme transcendental pleasure; and {3} ‘Rama’ means He who is the personification of all transcendental bliss.

(13) mantro guhyah paramo bhakti-vedyah.

“The maha-mantra is the topmost and most confidential of all mantras. It can only be understood when one engages in the pure devotional service of the Supreme Lord.

(14) namany ashtav-ashta ca shobhanani, tani nityam ye japanti dhiras. te vai mayam atitaranti, 'nanyah paramam-mantram parama-rahasyam nityam avartayati.

“Those who seriously desire to make progress in spiritual life should continually chant these sixteen beautiful names (maha-mantra) of the Supreme Personality of Godhead, and in this way they will cross beyond the bondage of the illusory enery in this material world. There is no other mantra which is as powerful as this supremely great and most confidential of all mantras, which has directly descended from the spiritual world.”