Mandukya Karika, verse 4.79
Text
अभूताभिनिवेशाद्धि सदृशे तत्प्रवर्तते ।
वस्त्वभावं स बुध्वैव निःसंगं विनिवर्तते ॥ ७९ ॥
abhūtābhiniveśāddhi sadṛśe tatpravartate |
vastvabhāvaṃ sa budhvaiva niḥsaṃgaṃ vinivartate || 79 ||
79. On account of attachment to the unreal objects, the mind runs after such objects. But it comes back (to its own pure state) when it becomes unattached (to objects) realising their unreality.
Shankara Bhashya (commentary)
Attachment to the unreal (objects) is due to the firm belief that duality exists, though in reality such duality is ever non-existent. On1 account of such attachment which is of the nature of delusion caused by ignorance, the mind runs after objects corresponding to those desires. But when a man knows the unreality2 of all duality of objects, then he becomes indifferent to them and turns away his mind from the unreal (objects) to which he feels attached.