Skandapurana 5.79.158_24

5.79.158_24

tatkathaṃ maṃtravīryaṃ tatkriyate moghamityaho ..
vedoktaṃ ca viśeṣeṇa tasmādatra vada prabho .. 39 ..

Then how can that power of mantras be rendered futile? / Especially since it is spoken in the Veda; therefore, tell us here, O lord!