Skanda Purana — Nagara Khanda, Shloka 21
अवध्यः सर्वभूतानां मानुषाणां विशेषतः । मुक्त्वैकां योषितं तेन त्वमस्माभिर्विनिर्मिता
avadhyaḥ sarvabhūtānāṃ mānuṣāṇāṃ viśeṣataḥ | muktvaikāṃ yoṣitaṃ tena tvamasmābhirvinirmitā
「彼はあらゆる生きとし生けるものにとって不殺（ころせぬ）者――とりわけ人間には無敵である。唯一の一人の女を除いては討たれぬゆえ、汝はわれらによって造り出されたのだ。」
Devas
Scene: A council of gods reveals the enemy’s boon: invincible to beings, especially men, except for one woman; the gods ‘fashion’/resolve the emergence of a feminine slayer as the destined remedy.
FAQs
Adharma’s seeming invincibility is limited; divine justice arises precisely through the ‘exception’ that restores balance.
This verse is mythic rationale within the Tīrtha-māhātmya frame; the Vindhya setting becomes explicit immediately afterward.
None; it explains the boon-condition that necessitates the Goddess’s manifestation.