Mahabharata 3.218.26

3.218.26

āgamya manujavyāghra saha devyā paraṃtapa |
arcayāmāsa suprīto bhagavāngovṛṣadhvajaḥ || 26 ||

Markandeya continued, "Thus anointed by Indra and all other gods, and honoured by the Maharshis, he looked grand at the moment. The golden umbrella held (over his head) looked like a halo of blazing fire. That famous god, the Conqueror of Tripura, himself fastened the celestial wreath of gold, of Viswakarma's manufacture, round his neck. And, O great man and conqueror of thine enemies, that worshipful god with the emblem of the bull, had gone there previously with Parvati. He honoured him with a joyous heart. The Fire-god is called Rudra by Brahmanas, and from this fact Skanda is called the son of Rudra. The White Mountain was formed from discharges of Rudra's semen virile and the sensual indulgences of the Fire-god with the Krittikas took place on that same White Mountain. And as Rudra was seen by all the dwellers of heaven to heap honours on the excellent Guha (Skanda), he was for that reason reputed as the son of Rudra. This child had his being by the action of Rudra entering into the constitution of the Fire-god, and for this reason, Skanda came to be known as the son of Rudra. And, O Bharata, as Rudra, the Fire-god, Swaha, and the six wives (of the seven Rishis) were instrumental to the birth of the great god Skanda, he was for that reason reputed as the son of Rudra.