Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 12
Sanskrit:
रजस्तमोभ्यां यदपि विद्वान् विक्षिप्तधी: पुन: ।अतन्द्रितो मनो युञ्जन् दोषदृष्टिर्न सज्जते ॥ १२ ॥
ITRANS:
rajas-tamobhyāṁ yad apividvān vikṣipta-dhīḥ punaḥatandrito mano yuñjandoṣa-dṛṣṭir na sajjate
Translation:
Although the intelligence of a learned person may be bewildered by the modes of passion and ignorance, he should again carefully bring the mind under control. By clearly seeing the contamination of the modes of nature, he does not become attached.