As Rudra was seen by all the dwellers of heaven to honour Guha (Skanda), the foremost of all accomplished beings is for this reason called the son of Rudra.
पूज्यमानं तु रुद्रेण दृष्ट्वा सर्वे दिवौकसः। रुद्रसूनुं ततः प्राहुर्गुहं गुणवतां वरम्॥