CC Madhya 20.317

brahmā, śiva — ājñā-kārī bhakta-avatāra
pālanārthe viṣṇu — kṛṣṇera svarūpa-ākāra
Word for word: 
brahmā — Lord Brahmā; śiva — Lord Śiva; ājñā-kārī — order-carriers; bhakta-avatāra — incarnations of devotees; pālana-arthe — for maintenance; viṣṇu — Lord Viṣṇu; kṛṣṇera — of Lord Kṛṣṇa; svarūpa-ākāra — in the form of a personal feature.
Translation: 
“The conclusion is that Lord Brahmā and Lord Śiva are simply devotee incarnations who carry out orders. However, Lord Viṣṇu, the maintainer, is the personal feature of Lord Kṛṣṇa.