Īśopaniṣad Mantra 9 · ईशोपनिषद् मन्त्र 9
अन्धं तमः प्रविशन्ति येऽविद्यामुपासते । ततो भूय इव ते तमो य उ विद्यायां रताः ॥
andhaṁ tamaḥ praviśanti ye 'vidyām upāsate | tato bhūya iva te tamo ya u vidyāyāṁ ratāḥ ||
Meaning
Into blinding darkness they enter who worship avidyā; into greater darkness still, they who delight only in vidyā.