Patanjali's yoga sutras

ध्रुवे तद्गतिज्ञानम् ॥ ३.२७ ॥

3.28 dhruve tadgatijñānam

dhruve = on the pole-star

tad = of their

gati = movement

jñānam = the knowledge

By meditating on the pole star, you gain insights into their movement.