na mayy upaiṣyaty ari-buddhim acyutaḥ
kaḿsasya dūtaḥ prahito 'pi viśva-dṛk
yo 'ntar bahiś cetasa etad īhitaḿ
kṣetra-jña īkṣaty amalena cakṣuṣā
na -- not; mayi -- toward me; upaishyati -- will He develop; ari -- of being an enemy; buddhim -- the attitude; acyutah -- the infallible Lord; kamsasya -- of Kamsa; dutah -- a messenger; prahitah -- sent; api -- although; visva -- of everything; drik -- the witness; yah -- who; antah -- inside; bahih -- and outside; cetasah -- of the heart; etat -- this; ihitam -- whatever is done; kshetra -- of the field (of the material body); jnah -- the knower; ikshati -- He sees; amalena -- with perfect; cakshusha -- vision.
Being omniscient, Lord Krishna knew that Akrura was only externally a friend of Kamsa. Internally he was an eternal devotee of Lord Krishna.