CC Madhya 20.105

kṛṣṇa-śakti dhara tumi, jāna tattva-bhāva
jāni’ dārḍhya lāgi’ puche, — sādhura svabhāva
Word for word: 
kṛṣṇa-śakti — the energy of Lord Kṛṣṇa; dhara — possess; tumi — you; jāna — know; tattva-bhāva — the factual position; jāni’ — although knowing all these things; dārḍhya lāgi’ — for the sake of strictness; puche — he inquires; sādhura — of a saintly person; svabhāva — the nature.
Translation: 
“Since you possess Lord Kṛṣṇa’s potency, you certainly know these things. However, it is the nature of a sādhu to inquire. Although he knows these things, the sādhu inquires for the sake of strictness.