Srila Prabhupada

Prabhupāda: Parama koruṇa, pahū dui jana, nitāi gauracandra. This is a song by Locana dāsa Ṭhākura, a great devotee and ācārya of the Gauḍīya-sampradāya. He is declaring that pahū dui jana. Pahū means lords. Dui jana means two. Who are the two Lords? Nitāi Gauracandra. One is Lord Nitāi, Nityānanda; another is Lord Śrī Caitanya Mahāprabhu.
So he says that, “These two Lords are very merciful.” Parama koruṇa, pahū dui jana. Parama koruṇa means very merciful. Nitai Gauracandra. Saba avatāra, sāra śiromaṇi. Avatāra means incarnation, and saba means all. “They are the essence of all incarnations.” Saba avatāra, sāra śiromaṇi, kevala ānanda-kanda: “And the specific significance of these incarnations is that to prosecute Their ways of self-realization is simply joyful,” ānanda-kanda.
They introduced chanting and dancing. No other incarnation . . . there are many incarnation, just like Lord Rāma. Even Kṛṣṇa, He taught Bhagavad-gītā. That requires knowledge, understanding. But here Lord Caitanya, Nityānanda, introduced some process which is simply joyful: simply chant and dance. Kevala ānanda-kanda. Saba avatāra, sāra śiromaṇi, kevala ānanda-kanda.
Therefore he requests everyone, bhajo bhajo bhāi, caitanya nitāi: “My dear brothers, I request you. Just you worship Lord Caitanya and Nityānanda” sudṛḍha biśwāsa kori’, “with firm conviction and faith” Don’t think that this chanting and dancing will not lead you to the desired goal. It will, because there is assurance of Lord Caitanya Mahāprabhu that you will get all perfection by this process. Therefore Locana dāsa Ṭhākura says that "You must have firm faith and conviction." It will act.
(690104 – Lecture Purport to Parama Koruna – Los Angeles)