Lord Krishna bestowed the nectar of Gita to humanity through his great loving devotee Arjuna. Arjuna surrendered to Krishna saying, “Karishye vachanam thava- I shall act as per your word or command”. Even a great one like him developed, on one occasion, a bit of ego. Arjuna was in a triumphant mood by the end of ninth day of the Mahabharat war.
The chariot had returned to the base camp. It was the custom in those days that the driver of the chariot would get down first and only then the master would get down from the chariot.
In a fit of triumphant ego, Arjuna asked Krishna to get down first reminding him of the custom. Krishna pretended anger and asked Arjuna to get down at once and to stand at a fair distance. Arjuna was bitten by a streak of shame, but obeyed Krishna implicitly. Then Krishna jumped out of the chariot. No sooner he jumped out, the chariot was inflamed and in minutes it became a heap of ash. Arjuna was stunned at it and asked, “What is this incredible happening?” Krishna smiled and explained, “I trounced and held under my feet all the Aagneya astras (weapons of fire) discharged by Bhishma towards you during all these days of the war. This is the reason why I asked you to get down first”. Arjuna fell at his feet, asked for a pardon and expressed his gratitude to Krishna for having saved him time and again.
It is out of love that he reprimands or punishes his devotees. God is always beholden to his devotees. Humanity would not have understood the principle of love if there were no Avtars.