Though incited by Krsna who was testing Arjuna’s sense of justice, Arjuna did not want to kill him, even though he had killed his son (atma-hanam), because he was intelligent (mahan) - he knew the nature of Krsna. Krsna’s nature is that, though he is omniscient, he tests the devotees in this way in order to show their sense of justice to others. He tests Arjuna, possessor of dharma, by showing vira and raudra rasas when he says “You should not release him.” (SB 1.7.35)

In the same way he tested the gopis, possessors of prema, by showing karma and jnana in such verses as bhartuh susrusanam strinam paro dharmah: the highest religious duty for a woman is to sincerely serve her husband (SB 10.29.24); bhavatinam viyogo me na hi sarvatmana kvacit: you are never actually separated from me, for I am the Soul of all creation (SB 10.47.29); aham hi sarva-bhutanam adir anto ’ntaram bahih: dear ladies, I am the beginning and end of all created beings and exist both within and without them. (SB 10.82.45)

He also tested Prthu, Prahlada and others, who were filled with devotion, by showing or promising enjoyment and powers to them. Varam ca mat kancana manavendra vrnisva: dear Prthu, you may therefore ask from me any benediction you like. (SB 4.20.16) Varam vrnisvabhimatam kama-puro ’smy aham nrnam: it is my pastime to fulfill the desires of all living beings, and therefore you may ask from me any benediction that you desire to be fulfilled. (SB 7.9.52) Diyamanam na grhnanti: though I offer these benedictions, they do not accept. (SB 3.29.13 )

Even his siddha devotees test others. Thus Sukadeva tests Pariksit. In the Sixth Canto, he tests his knowledge of siddhanta when he speaks of regular atonements when Pariksit asks the method of getting free of sin. In the Ninth Canto, Sukadeva tests Pariksit’s eagerness for Krsna’s pastimes by summarizing those pastimes, and in the Twelfth Canto, he tests his steadiness in bhakti by talking of brahma-jnana. The real meaning is not always in the directly observed events.