He is the One Who made the sun a hot light and the moon a light and determined phases of it in the order you to know the number of years and reckoning the time; Lord Allah has not created that except with Truth, He details His verse for a people having the Knowledge.
The sun is giving hot light and it is the source of energy while the moon is giving the reflecting light of the sun as told in verses 91: 1-2. It is told in verse 78: 13 that Lord made the sun as the burning lamp in the sky. Allah and Adhikr are denoted as the Light as explained 4: 174. Messenger Muhammad is denoted as reflecting lamp since he is reflecting the Light Adhikr to mankind as told in verse 33: 46. Lord has determined different phases for moon until it returns like the stalk of old date palm as told in verse 36: 39. It is for reckoning months and years. For calculating the day of fasting and Eid, the lunar calendar is satisfied by the Lord for the entire mankind. But the Arabic Qur’an reading disbelievers are not following the Qibla, and they are performing fasting and celebrating Eid on different days all over the world. Thus, these worthless people became the worshipers of the moon as explained in verse 9: 74. Islam, in all its aspects, will be implemented in this world only after the second coming of Jesus by wiping out the hypocrites and Kuffar as explained in verses 4: 158-159 and 9: 123. See theexplanations2: 145; 6: 96 and 9: 36-37.