CC Ādi 2.113

kṛṣṇake kahaye keha — nara-nārāyaṇa
keho kahe, kṛṣṇa haya sākṣāṭ vāmana
Synonyms: 
kṛṣṇake — Lord Kṛṣṇa; kahaye — says; keha — someone; nara-nārāyaṇa — Nara-Nārāyaṇa; keho — someone; kahe — says; kṛṣṇa — Lord Kṛṣṇa; haya — is; sākṣāt — directly; vāmana — Lord Vāmana.
Translation: 
Some say that Śrī Kṛṣṇa is directly Nara-Nārāyaṇa. Others say that He is directly Vāmana.