pārthivāviṣayatve hi tajjñānatvābhidhānataḥ tadyathā prathamaṃ jñānaṃ tat kālārkādigocaram
Because while not being a cognition of earthly objects, it is designated as the cognition of those [celestial objects], just like the first cognition [which pertained to] the sun etc. of that time.