The word nirantara, meaning “without cessation, continuously, constantly,” is very important in this verse. The word antara means “interval.” if one has desires other than a desire to perform devotional service-in other words, if one sometimes engages in devotional service and sometimes strives for sense gratification-his service will be interrupted. A pure devotee, therefore, should have no other desire than to serve Kṛṣṇa. He should be above fruitive activity and speculative knowledge.
Another meaning of antara is “this body.” The body is an impediment to self-realization because it is always engaged in sense gratification. Similarly, antara means “money.” If money is not used in Kṛṣṇa’s service, it is also an impediment. Antara also means janatā, “people in general.” The association of ordinary persons may destroy the principles of devotional service. Similarly, antara may mean “greed,” greed to acquire more money or enjoy more sense gratification. Finally, the word antara may also mean “atheistic ideas” by which one considers the temple Deity to be made of stone, wood or gold. All of these are impediments.
Ref >> Srila Prabhupada Vani.