Do not speak of a rhinoceros if there is no tree nearby.

Related:

• When you see a palm tree, the palm tree has seen you.
  African(Wolof)...
• Smooth seas do not make skillful sailors. --
  African...
• Lomhlaba Unzima, Lohmhlaba. [This world is a harsh place,
  this world.] Zulu...
• If you do not have patience you cannot make beer.
  African(Ovambo)...
• A parasite can not live alone
  African(Ovambo)...
• When there is no enemy within, the enemies outside cannot hurt you.
  African...
• When two elephants fight, it is the grass that suffers.
  East African...
• The country rooster dows not crow in the town.
  African(Swahili)...