It is He Who made the sun a shining thing and the moon as a light and measured out its (their) stages, that you might know the number of years and the reckoning. Allah did not create this but in truth. He explains the Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.) in detail for people who have knowledge. Verily, in the alternation of the night and the day and in all that Allah has created in the heavens and the earth are Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.) for those people who keep their duty to Allah, and fear Him much.