CC Madhya 21.42
tina āvāsa-sthāna kṛṣṇera śāstre khyāti yāra
“This is the middle meaning. Now please hear the confidential meaning. Lord Kṛṣṇa has three places of residence, which are well known from the revealed scriptures.
Kṛṣṇa has three abodes — His internal abode (Goloka Vṛndāvana), His intermediate abode (the spiritual sky) and His external abode (this material world).