Patanjali Yoga Sutra 2.54

Sanskrit Sutra

स्वस्वविषयासम्प्रयोगे चित्तस्वरूपानुकार इवेन्द्रियाणां प्रत्याहारः॥५४॥

Swami Vivekananda's translation

The drawing in of the organs is by their giving up their own objects and taking the form of the mind-stuff, as it were.

Chapter link: Yoga Sutra Chapter 2