Śrī Caitanya Mahāprabhu, who established the chanting of śrī harināma saṅkīrtana, instructs the bhaktas to perform saṅkīrtana of the mahā-mantra.
sanvīkṣya gauro hari-nāma-mantraṃ
svayaṃ dadau bhakta-janān samā-diśat
saṅkīrtaya dvaṃ nanu nṛtya-vādhyaiḥ
“Out of His causeless mercy, Śrī Caitanya Mahāprabhu Himself gave the mahā-mantra to the helpless, fearful jīvas of this Kali-yuga, and directed His devotees by saying, ‘O bhaktas, you should collectively perform saṅkīrtana by singing and dancing.’ ”
upadeṣṭā svayaṃ kṛṣṇa caitanyo jagadīśvaraḥ
kṛṣṇa-caitanya-devena hari-nāma-prakāśitam
yena kenāpi tat-praptaṃ dhanyo’ sau loka-pāvanaḥ
“By the mercy of hari-nāma, a sinner can also be delivered because the instructor of śrī hari-nāma is the Lord of the universe, Svayaṃ Śrī Kṛṣṇa Caitanya Mahāprabhu. Therefore, a person who is fortunate enough to receive this hari-nāma, which has been inaugurated by Śrī Kṛṣṇa Caitanya Mahāprabhu Himself, can also purify others by his association.”
The great poet Śrīla Kavi Karṇapūra states in his epic poem,
Caitanya-Caritā (11-54):
hare kṛṣṇa hare kṛṣṇa kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma rāma rāma hare hare
“At the time of Śrī Caitanya Mahāprabhu’s sannyāsa ceremony, the barber who had been asked to shave Him felt morose and was perturbed. Although he held the razor in his hand, he could not bring himself to shave off Śrī Caitanya Mahāprabhu’s beautiful hair. Instead he simply wept. Śrī Caitanya Mahāprabhu, who was fully immersed in rādhā-bhāva, became deeply pleased and said, ‘O Barber! You must constantly and loudly chant hare kṛṣṇa hare kṛṣṇa kṛṣṇa kṛṣṇa hare hare hare rāma hare rāma rāma rāma hare hare.’ Upon hearing these instructions from Śrī Mahāprabhu, that barber began to chant, and, although he continued to weep in distress, he proceeded to shave off Mahāprabhu’s hair. He became so absorbed in chanting the mahā-mantra that he manifested horripilation (romañca) and his bodily hairs stood erect (pulaka).”
tāra ghare bhakti bhare gāna āraṃbhilā
brāhmaṇera ghara yena haila vṛndāvana
hari-nāma śunibāre āise sarva-jana
hare kṛṣṇa hare kṛṣṇa kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma rāma rāma hare hare
“Once Mahāprabhu visited the home of a brāhmaṇa and embraced him. The kīrtana that followed made that home become just like Vrndāvana and a multitude of people gathered to hear and chant the mahā-mantra: hare kṛṣṇa hare kṛṣṇa kṛṣṇa kṛṣṇa hare hare harerāma hare rāma rāma rāma hare hare.”
prasanna śrī mukhe hare kṛṣṇa kṛṣṇa bali
vijaya hailā gauracandra kutūhalī
pratyakṣa haila āsi advaita-sammukhe
“Śrī Caitanya Mahāprabhu is always chanting śrī nāma. One day when He came to the home of Advaita Ācaryā, His face filled with pleasure as He chanted the hare kṛṣṇa mahā-mantra.”
yei jape tāre kṛṣṇe upajaye bhāva
“The nature of the hare kṛṣṇa mahā-mantra is such that when a person chants it, he immediately develops his loving ecstatic relationship with Kṛṣṇa.”
yāra āge tṛṇa-tulya cāri puruṣārtha
“When the four goals of human life, dharma (perfectly performing one’s occupational duty), artha (accumulating wealth), kāma (satisfying one’s sensual desires) and mokṣa (attaining liberation), stand before kṛṣṇa prema, the fifth and topmost goal, they appear as insignificant as straw in the street.“
brahmādi ānanda yāra nahe eka bindu”
“The pleasure derived from dharma, artha, kāma and mokṣa appear like a drop in the ocean in the presence of a person who has developed bhāva.”
“kṛṣṇa-nāmera phal’ premā, sarva śāstre kaya”
(C.c. Ādi-līlā 7. 86)
“The conclusion of all śāstra is that one should awaken his dormant kṛṣṇa-prema.”
nāma haite haya sarva-jagat-nistāra
“The holy name of Bhagavān, the hare kṛṣṇa mahā-mantra, is His avatāra in this age of Kali. Just by chanting this name, one associates with Śrī Kṛṣṇa directly. Anyone who does this is certainly delivered.”
kali kāle dharma—kṛṣṇa-nāma-saṅkīrtana
“Śrī Caitanya Mahāprabhu has descended in Kali-yuga to propagate the dharma of the age, chanting the holy names of Kṛṣṇa.”
sei ta sumedhā āra—kali-hata-jana
“A person who worships Śrī Caitanya Mahāprabhu by performing saṅkīrtana should be considered to possess great intelligence. It is understood that one who does not perform saṅkīrtana has no intelligence and is a victim of Kali.”
helāya mukti pābe, pabe prema-dhana
“Always chant kṛṣṇa-nāma and you will very easily achieve mukti. Finally you will receive the treasure of kṛṣṇa-prema.”
āra ‘nāma’ la-ite kṛṣṇa-caraṇa-pāibe
“Begin to chant the hare kṛṣṇa mahā-mantra and, at the stage of nāmabhasa, when your chanting is almost pure, all your sinful reactions will be removed. When you perfectly chant hare kṛṣṇa, you will attain the shelter of Śrī Kṛṣṇa’s lotus feet.”
nāmera phale kṛṣṇa-pade prema upajaya
(C.c. Antya-līlā 3.178)
“The result of chanting nāma without offence is that a person will awaken his ecstatic love for the lotus feet of Kṛṣṇa.”
kali-kālera dharma—kṛṣṇa-nāma-saṅkīrtana
(C.c. Antya-līlā 7.11)
“In Kali-yuga the dharma is to chant kṛṣṇa-nāma-saṅkīrtana.”
nāma-saṅkīrtana-kalau parama upāya
“In great jubilation Śrī Caitanya Mahāprabhu said, ‘My dear Svarūpa Dāmodara and Rāmānanda Rāya, understand that the easiest way to attain mokṣa in this age of Kali is by chanting hari-nāma.’ ”
sei ta sumedhā pāya kṛṣṇera caraṇa
“In this age of Kali, the system for worshipping Kṛṣṇa is to perform yajña by chanting Śrī Bhagavān’s name. Someone who does so is considered to be intelligent, and he will definitely attain the lotus feet of Kṛṣṇa.”
sarva-śubhodaya kṛṣṇa-premera ullāsa
“By chanting kṛṣṇa-nāma, one can eradicate all anarthas. In this way all good fortune is awakened and the flow of kṛṣṇa-prema begins.”
kāla-deśā-niyama nāhi sarva siddhi haya
“One who chants the name while eating or sleeping, regardless of time or place, attains all perfection.”
śrī kṛṣṇa-caraṇe tāṅra prema upajaya
“A person will definitely awaken prema for the lotus feet of Śrī Kṛṣṇa if he chants krṣṇa-nāma like this.”
Śrīla Raghunātha dāsa Gosvāmī states in the introduction to his commentary on the mahā-mantra:
manovāṣpanirāsārthaṃ jalpatīdaṃ muhurmuhuha
hare kṛṣṇa hare kṛṣṇa kṛṣṇa kṛṣṇa hare hare
hare rāma hare rāma rāma rāma hare hare
yāni nāmāni virahe jajāpa vārṣabhānavī
tānye va tadbhāvayukto gauracandro jajāpa ha
śrī caitanya-mukhod gīrṇa hare kṛṣṇeti varṇakaḥ
majjayanto jagat premṇi vijayantāṃ tadā vayāḥ
“Once, Śrīmatī Rādhikā was feeling overwhelming distress due to separation from Her beloved Śyāmasundara and She meditated upon meeting Him. To remove Her fire of separation, She began to chant the hare kṛṣṇa mahā-mantra. Śrī Caitanya Mahāprabhu, who is absorbed in the mood of Śrīmatī Rādhikā, also chanted these names. Thus, Kṛṣṇa’s sixteen names consisting of thirty-two syllables, the hare kṛṣṇa mahā-mantra, came from the lotus mouth of Śrī Caitanya Mahāprabhu. May this mahā-mantra, which makes the entire universe become absorbed in kṛṣṇa-prema, be graciously and conspicuously present above all else. Jaya ho! Jaya ho! Let there be complete victory for the mahā-mantra!”
Reference to the mahā-mantra is also found in the Brahmāṇḍa
Purāṇa, Uttara-khaṇḍa, 6.55:
hare rāma hare rāma rāma rāma hare hare
“The three names, Hare, Kṛṣṇa, and Rāma, which are in the vocative case, comprise the mahā-mantra.”
The following ślokas from Caitanya Bhagavata also show the supremacy of hari-nāma: (Ādi 14.137,139-143), (Madhya 6.117), (Madhya 23.74-78) and (Madhya 28.28).