B.G 2.23
नैनं छिन्दन्ति शस्त्राणि नैनं दहति पावकः। न चैनं क्लेदयन्त्यापो न शोषयति मारुतः ॥ २-२३॥
Weapons cannot cut Him, fire cannot burn Him, water cannot drench Him, not even wind can dry Him.
Gīta Bhāshya 2.23
Both internal natural causes and external special causes cannot destroy the Lord
स्वतः प्रायोनिमित्तैश्च अविनाशिनोऽपि केनचिन्निमित्त विशेषेण स्यात्। ककच्छेदवत् इत्यतो विशेषनिमित्तानि निषेधति– 'नैनम्' इति ॥ २३ ॥
It is indestructible because not only it cannot be destroyed by natural causes, originating from themselves, but also by particular external causes. By rejecting it can be pierced, the verse 'nainam' forbids the possibility of its destruction by special causes.
Gīta Tātparya 2.23
Various external cases cannot destroy the Lord
कारणतोपि न ईश्वरस्य अन्यथात्वमित्याह - नैनं छिन्दन्तीति ॥२३॥
The verse 'nainam chindanti', not possible to pierce, clarifies there is no destruction to the Lord by various external causes.