Srimad Bhagavatam Canto 10, Chapter 38, Text 18

SB 10.38.18

na mayy upaisyaty ari-buddhim acyutah
 kamsasya dutah prahito ’pi visva-drk
yo ’ntar bahis cetasa etad ihitam
 ksetra-jña iksaty amalena caksusa
 
Translation: 
 
The infallible Lord will not consider me an enemy, even though Kamsa has sent me here as his messenger. After all, the omniscient Lord is the actual knower of the field of this material body, and with His perfect vision He witnesses, both externally and internally, all the endeavors of the conditioned soul’s heart.
 
Purport: 
 
Being omniscient, Lord Krsna knew that Akrura was only externally a friend of Kamsa. Internally he was an eternal devotee of Lord Krsna.
Srimad Bhagavatam Canto 10, Chapter 38, Text 17
Srimad Bhagavatam Canto 10, Chapter 38, Text 19