[Advaita-l] Brahma's son incarnates as Shiva's son - Sanatkumara-Skanda identity

[V Subrahmanian]

https://youtu.be/CDvuYml-Tms

In this short, crisp, Tamil discourse (of just 10 minutes), the young
Srivaishnava scholar recounts a story that is the basis for Sanatkumara,
thru his own boon to Shiva, incarnates as Skanda.

The scholar refers to the text 'Tripura Rahasya'  (Mahatmya Khanda 37th
chapter) for the story.  Could anyone please fish out that story,
preferably in English for the benefit of all?

Shankara has referred to just the boon-incarnating incident and has not
alluded to the story.  BSB: 3.3.32:

सनत्कुमारोऽपि ब्रह्मण एव मानसः पुत्रः स्वयं रुद्राय वरप्रदानात् स्कन्दत्वेन
प्रादुर्बभूव ;

[Even Sanatkumara, the mind-born son of Brahmaa, due to his own boon to
Rudra, incarnated as Skanda.]

warm regards
subbu