Viṣṇujana: "In the Nārada Pañcarātra this is confirmed in this way: 'By concentrating one's attention on the transcendental form of Kṛṣṇa, who is all-pervading and beyond time and space, one becomes absorbed in thinking of Kṛṣṇa and then attains the happy state of transcendental association with Him.' Kṛṣṇa consciousness is the highest stage of trance in yoga practice. This very understanding that Kṛṣṇa is present as Paramātmā in everyone's heart makes the yogi faultless. The Vedas confirm this inconceivable potency of the Lord as follows: 'Viṣṇu is one and yet He is certainly all-pervading. By His inconceivable potency, in spite of His one form, He is present everywhere. As the sun, He appears in many places at once.' "
Prabhupāda: Yes, that example I have already given. As the sun can be present in many places simultaneously, similarly, Viṣṇu form or Kṛṣṇa can be present in everyone's heart, He is actually present: īśvaraḥ sarva-bhūtānāṁ hṛd-deśe 'rjuna (BG 18.61)—He's sitting. The localization is also stated. Hṛd-deśe. Hṛd-deśe means in the heart. So concentration of yoga means to find out from the heart where Viṣṇu is sitting. There is. Go on.