Patanjali Yog Sutras

patanjali yoga sutra
samadhipad
Sutra 4

sutra 4 vritti saaroopyam itaratra
vritti saaroopyam itaratra

Translation: (the awastha of drashta is) has similar form (saaroopyam) as the vritti at other times (itaratra)

The manifested word is temporary and so are all its aspects. The senses which perceive the various aspects of physical world as pain/pleasure are also temporary. They fade with age. Vrittis which are further modifications of the mind are primarily to do with the temporary only. So when the mind is on the temporary, the permanent which is your true swaroop becomes unperceivable. So it is imperative to look inwards and focus on your true swaroop to experience reality.