Because they (puzzled people who visited Sri Caitanya Mahaprabhu) were speculating with their imperfect knowledge, they saw Sri Caitanya Mahaprabhu as an ordinary human being and a boatman's light in the lake as Krsna

Expressions researched:
"Because they were speculating with their imperfect knowledge, they saw Śrī Caitanya Mahāprabhu as an ordinary human being and a boatman's light in the lake as Kṛṣṇa"

Sri Caitanya-caritamrta

CC Madhya-lila

The puzzled people who visited Śrī Caitanya Mahāprabhu were actually seeing Lord Kṛṣṇa, but they were mistaken in thinking that Lord Kṛṣṇa had come to Kālīya Lake. They all said that they had seen Kṛṣṇa directly performing His pastimes on the hoods of the serpent Kālīya and that the jewels on Kālīya’s hoods were blazing brilliantly. Because they were speculating with their imperfect knowledge, they saw Śrī Caitanya Mahāprabhu as an ordinary human being and a boatman’s light in the lake as Kṛṣṇa.

CC Madhya 18.99, Translation and Purport

At that time Balabhadra Bhaṭṭācārya placed a request at the lotus feet of Śrī Caitanya Mahāprabhu. He said, “Please give me permission to go see Lord Kṛṣṇa directly.”

The puzzled people who visited Śrī Caitanya Mahāprabhu were actually seeing Lord Kṛṣṇa, but they were mistaken in thinking that Lord Kṛṣṇa had come to Kālīya Lake. They all said that they had seen Kṛṣṇa directly performing His pastimes on the hoods of the serpent Kālīya and that the jewels on Kālīya’s hoods were blazing brilliantly. Because they were speculating with their imperfect knowledge, they saw Śrī Caitanya Mahāprabhu as an ordinary human being and a boatman’s light in the lake as Kṛṣṇa. One must see things as they are through the mercy of a spiritual master; otherwise, if one tries to see Kṛṣṇa directly, he may mistake an ordinary man for Kṛṣṇa or Kṛṣṇa for an ordinary man. Everyone has to see Kṛṣṇa according to the verdict of Vedic literatures presented by the self-realized spiritual master. A sincere person is able to see Kṛṣṇa through the transparent via medium of Śrī Gurudeva, the spiritual master. Unless one is enlightened by the knowledge given by the spiritual master, he cannot see things as they are, even though he remains constantly with the spiritual master. This incident at Kālīya-daha is very instructive for those eager to advance in Kṛṣṇa consciousness.