Verily, in the creation of the heavens and the earth, and in the alternation of night and day, and in the ship that sail the seas with that which profits mankind, and in the rain which Allah sends down from heaven and quickens therewith the earth after its death, and spreads abroad therein all kinds of animals, and in the shifting of the winds, and in the clouds that are pressed into service betwixt heaven and earth, are signs for people who can understand.