"It is He who made the sun a shining light and the moon a derived light and determined for it phases," meaning: He made for the moon phases among the stars, which are twenty-eight phases in every month, meaning: the moon, "that you may know the number of years and account [of time]" by night and by day. "Allah has not created this except in truth," meaning: indeed, this leads to the hereafter. "He details the signs"—He makes them clear—"for a people who know," and they are the believers.