SB 5.23.8
etad u haiva bhagavato visnoh sarva-devatamayam rupam aharahah sandhyayam prayato vagyato
niriksamana upatistheta namo jyotir-lokaya kalayanayanimisam pataye maha-purusayabhidhimahiti.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
My dear King, the body of the sisumara, as thus described, should be considered the external form of Lord Visnu, the Supreme Personality of Godhead. Morning, noon and evening, one should silently observe the form of the Lord as the Sisumara-cakra and worship Him with this mantra: “O Lord who have assumed the form of time! O resting place of all the planets moving in different orbits! O master of all demigods, O Supreme Person, I offer my respectful obeisances unto You and meditate upon You.”