Because of the movements of the water, the trees on the bank of a river, when reflected on the water, seem to move. Similarly, when the eyes move because of some mental derangement, the land appears to move also.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
यथाम्भसा प्रचलता तरवोऽपि चला इव । चक्षुषा भ्राम्यमाणेन दृश्यते चलतीव भूः
yathāmbhasā pracalatā taravo'pi calā iva | cakṣuṣā bhrāmyamāṇena dṛśyate calatīva bhūḥ
SB 7.2.23