Here is the beginning of competition between brahma-tejas and siva-tejas. By brahma-tejas, brahminical strength, Bhrgu Muni had created the Rbhu demigods, who had driven away the soldiers of Lord Siva stationed in the arena. When Lord Siva heard that his soldiers had been driven away, he created the tall black demon Virabhadra to retaliate. There is sometimes a competition between the mode of goodness and the mode of ignorance. That is the way of material existence. Even when one is situated in the mode of goodness, there is every possibility that his position will be mixed with or attacked by the mode of passion or ignorance. That is the law of material nature. Although pure goodness, or suddha-sattva, is the basic principle in the spiritual world, pure manifestation of goodness is not possible in this material world. Thus, the struggle for existence between different material qualities is always present. This quarrel between Lord Siva and Bhrgu Muni, centering around Prajapati Daksa, is the practical example of such competition between the different qualitative modes of material nature.