The words haṁsena yānena are very significant here. Haṁsa-yāna, the airplane by which Brahmā travels all over outer space, resembles a swan. Brahmā is also known as Haṁsa because he can grasp the essence of everything. His abode is called tri-dhāma-paramam. There are three divisions of the universe — the upper planetary system, the middle planetary system and the lower planetary system — but his abode is above even Siddhaloka, the upper planetary system. He returned to his own planet with the four Kumāras and Nārada because they were not going to be married. The other ṛṣis who came with him, such as Marīci and Atri, remained there because they were to be married to the daughters of Kardama, but his other sons — Sanat, Sanaka, Sanandana, Sanātana and Nārada — went back with him in his swan-shaped airplane. The four Kumāras and Nārada are naiṣṭhika-brahmacārīs. Naiṣṭhika-brahmacārī refers to one who never wastes his semen at any time. They were not to attend the marriage ceremony of their other brothers, Marīci and the other sages, and therefore they went back with their father, Haṁsa.