Haridāsa Ṭhākura is mentioned here as the most learned scholar, parama-vidvān. Actually, the most important science to know is the science of getting out of the clutches of material existence. Anyone who knows this science must be considered the greatest learned person. Anyone who knows the temporary situation of this material world and is expert in achieving a permanent situation in the spiritual world, who knows that the Supreme Personality of Godhead is beyond the jurisdiction of our experimental knowledge, is understood to be the most learned scholar. Haridāsa Ṭhākura knew this science perfectly. Therefore, he is described in this connection as parama-vidvān. He personally preached the importance of chanting the Hare Kṛṣṇa mahā-mantra, which is approved by the revealed scriptures. As stated in the Śrīmad-Bhāgavatam (7.5.24):

iti puṁsārpitā viṣṇau bhaktiś cen nava-lakṣaṇā
kriyeta bhagavaty addhā tan manye ’dhītam uttamam

There are nine different processes of devotional service to Kṛṣṇa, the most important being śravaṇaṁ kīrtanam — hearing and chanting. Haridāsa Ṭhākura knew this science very well, and he can therefore be called, technically, sarva-śāstrādhītī. Anyone who has learned the essence of all the Vedic scriptures is to be known as a first-class educated person, with full knowledge of all śāstra.