This is a prayer to Lord Caitanya. The devotee is saying, "O Lord Śrī Caitanya Mahāprabhu, kindly show me Your causeless mercy." Śrī-kṛṣṇa-caitanya prabhu doyā koro more, "Because You have come to deliver fallen souls, so You will not find the most fallen soul like me." This is the humble prayer. We should be conscious of our fallen condition and pray to the Lord in that way, that "My dear Lord, somehow or other I am fallen. Now kindly pick me up."
The substance of this song is like this. Of course, the language, Sanskrit, you may understand . . . , you may not understand, but the vibration will act.