Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 47
Sanskrit:
मनोवशेऽन्ये ह्यभवन् स्म देवामनश्च नान्यस्य वशं समेति ।भीष्मो हि देव: सहस: सहीयान्युञ्ज्याद वशे तं स हि देवदेव: ॥ ४७ ॥
ITRANS:
mano-vaśe ’nye hy abhavan sma devāmanaś ca nānyasya vaśaṁ sametibhīṣmo hi devaḥ sahasaḥ sahīyānyuñjyād vaśe taṁ sa hi deva-devaḥ
Translation:
All the senses have been under the control of the mind since time immemorial, and the mind himself never comes under the sway of any other. He is stronger than the strongest, and his godlike power is fearsome. Therefore, anyone who can bring the mind under control becomes the master of all the senses.