הַמָּאֹ֤ור הַגָּדֹל֙ לְמֶמְשֶׁ֣לֶת הַיֹּ֔ום
The Great Light to rule the day
Though God did not name the lights, He designated a dominion in which each would be prominent. The light in the sky that defined the day would be much more magnificent than its partner of the night. In fact, the sun is over 400 thousand times brighter than its reflection off a full moon.
It is no wonder,then, that the sun is the ruler (Hebrew: מֶמְשָׁלָה memshalah; realm) of the day. The night is a subject kingdom, far less than anything in the daylight.