The same thing is confirmed in the Ādi Purāṇa by Kṛṣṇa. While addressing Arjuna He says, "Anyone who is engaged in chanting My transcendental name must be considered to be always associating with Me. And I may tell you frankly that for such a devotee I become easily purchased."
In the Padma Purāṇa also it is stated: "The chanting of the Hare Kṛṣṇa mantra is present only on the lips of a person who has for many births worshiped Vāsudeva." It is further said in the Padma Purāṇa: "There is no difference between the holy name of the Lord and the Lord Himself. As such, the holy name is as perfect as the Lord Himself in fullness, purity and eternity. The holy name is no material sound vibration, nor has it any material contamination." The holy name cannot, therefore, be chanted offenselessly by one who has failed to purify his senses. In other words, materialistic senses cannot properly chant the holy names of the Hare Kṛṣṇa mahā-mantra. But, by adopting this chanting process, one is given a chance to actually purify himself so that he may very soon chant offenselessly.
Caitanya Mahāprabhu has recommended that everyone chant the Hare Kṛṣṇa mantra just to cleanse the dust from the heart. If the dust of the heart is cleansed away, then one can actually understand the importance of the holy name. For persons who are not inclined to clean the dust from their heart and want to keep things as they are, it is not possible to derive the transcendental result of chanting the Hare Kṛṣṇa mantra. One should, therefore, be encouraged to develop his service attitude toward the Lord, because this will help him to chant without any offense. And so, under the guidance of a spiritual master, the disciple is trained simultaneously to render service and at the same time to chant the Hare Kṛṣṇa mantra. As soon as one develops his spontaneous service attitude, he can immediately understand the transcendental nature of the holy names of the mahā-mantra.
In the Padma Purāṇa there is a statement about the importance of living at holy places like Mathurā or Dvārakā. It is stated there: "To travel to different places of pilgrimage means to attain emancipation from material bondage. This emancipation, however, is not the highest perfectional stage. After attaining this liberated stage, one has to become engaged in devotional service to the Lord. After attainment of the brahma-bhūta (liberation) stage one can further advance to engagement in devotional service. So this attainment of transcendental loving devotional service to the Lord is the goal of life, and it can be achieved very easily for one who lives in Mathurā-maṇḍala even for a few seconds."
It is further said: "Who is that person who will not agree to worship the land of Mathurā? Mathurā can deliver all the desires and ambitions of the fruitive workers and of the salvationists, who desire to become one with the supreme Brahman. Certainly Mathurā will deliver the desires of the devotees, who simply aspire to be engaged in the devotional service of the Lord." In the Vedic literature it is also stated: "How wonderful it is that simply by residing in Mathurā even for one day, one can achieve a transcendental loving attitude toward the Supreme Personality of Godhead! This land of Mathurā must be more glorious than Vaikuṇṭha-dhāma, the kingdom of God!"