ekale īśvara-tattva caitanya-īśvara
bhakta-bhāvamaya tāṅra śuddha kalevara
ekale—only one person; īśvara-tattva—the supreme controller; caitanya—the supreme living force; īśvara—controller; bhakta-bhāva-maya—in the ecstasy of a devotee; tāṅra—His; śuddha—transcendental; kalevara—body.
Śrī Caitanya Mahāprabhu, who is the supreme controller, the one Personality of Godhead, has ecstatically become a devotee, yet His body is transcendental and not materially tinged.
There are different tattvas, or truths, including īśa-tattva, jīva-tattva and śakti-tattva. Īśa-tattva refers to the Supreme Personality of Godhead Viṣṇu, who is the supreme living force. In the Kaṭha Upaniṣad it is said, nityo nityānāṁ cetanaś cetanānām: the Supreme Personality of Godhead is the supreme eternal and the supreme living force. The living entities are also eternal and are also living forces, but they are very minute in quantity, whereas the Supreme Lord is the supreme living force and the supreme eternal. The supreme eternal never accepts a body of a temporary material nature, whereas the living entities, who are part and parcel of the supreme eternal, are prone to do so. Thus according to the Vedic mantras the Supreme Lord is the supreme master of innumerable living entities.
The Māyāvādī philosophers, however, try to equate the minute living entities with the supreme living entity. Because they recognize no distinctions between them, their philosophy is called Advaita-vāda, or monism. Factually, however, there is a distinction. This verse is especially meant to impart to the Māyāvādī philosopher the understanding that the Supreme Personality of Godhead is the supreme controller. The supreme controller, the Personality of Godhead, is Kṛṣṇa Himself, but as a transcendental pastime He has accepted the form of a devotee, Lord Caitanya Mahāprabhu.
As stated in the Bhagavad-gītā, when the Supreme Personality of Godhead Kṛṣṇa comes to this planet exactly like a human being, some rascals consider Him to be one of the ordinary humans. One who thinks in that mistaken way is described as mūḍha, or foolish. Therefore one should not foolishly consider Caitanya Mahāprabhu to be an ordinary human being. He has accepted the ecstasy of a devotee, but He is the Supreme Personality of Godhead. Since Caitanya Mahāprabhu, there have been many imitation incarnations of Kṛṣṇa who cannot understand that Caitanya Mahāprabhu is Kṛṣṇa Himself and not an ordinary human being. Less intelligent men create their own "Gods" by advertising a human being as God. This is their mistake. Therefore here the words tāṅra śuddha kalevara warn that Caitanya Mahāprabhu's body is not material but purely spiritual. One should not, therefore, accept Caitanya Mahāprabhu as an ordinary devotee, although He has assumed the form of a devotee. Yet one must certainly know that although Caitanya Mahāprabhu is the Supreme Personality of Godhead, because He accepted the ecstasy of a devotee one should not misunderstand His pastimes and place Him in exactly the same position as Kṛṣṇa. It is for this reason only that when Śrī Kṛṣṇa Caitanya Mahāprabhu was addressed as Kṛṣṇa or Viṣṇu He blocked His ears, not wanting to hear Himself addressed as the Supreme Personality of Godhead. There is a class of devotees called Gaurāṅga-nāgarī, who stage plays of Kṛṣṇa's pastimes using a vigraha, or form, of Caitanya Mahāprabhu. This is a mistake that is technically called rasābhāsa. While Caitanya Mahāprabhu is trying to enjoy as a devotee, one should not disturb Him by addressing Him as the Supreme Personality of Godhead.
Link to this page: https://prabhupadabooks.com/cc/adi/7/10