PURPORT

This verse is an explanation of the night of Brahma, which is the effect of the influence of time in touch with an insignificant portion of the modes of material nature in darkness. The dissolution of the three worlds is effected by the incarnation of darkness, Rudra, represented by the fire of eternal time which blazes over the three worlds. These three worlds are known as Bhur, Bhuvar and Svar (Svarga, Martya and Patala). The innumerable living entities merge into that dissolution, which appears to be the dropping of the curtain of the scene of the Supreme Lord's energy, and so everything becomes silent.