To deceive a diplomat speak the truth, he has no experience with it.

Related:

• Speak the truth, but leave immediately after. --
  Slovenian...
• Success has many friends.
  Greek...
• A man cannot speak but he judges himself..
  no man thoroughly understands a truth until he has...
• If you speak the truth, keep a foot in the stirrup.
  Turkish...
• It is good to know the truth,
  but it is better to speak of palm trees. Arab...
• Speak of the devil and he appears. --
  Italian...
• Speak of the devil and he appears.
  Italian...
• He who respects his parents never dies.
  Greek...
• He who suffers much will know much.
  Greek...