It was a favourite expression of Theophrastus that time was the most valuable thing that a man could spend.

Related:

• Time is the most valuable thing a man can
  spend. --...
• Time is the image of eternity. -- Diogenes Laertius (c.
  200 AD) -- Plato,...
• He calls drunkenness an expression identical with ruin.
  Diogenes Laertius (c. 200 AD) -- Pythagoras,...
• Diogenes said once to a person who was showing him a dial,
  "It is a very useful thing to save a man from being...
• One of the sophisms of Chrysippus was, "If you have not lost a thing,
  you have it." -- Diogenes Laertius (c. 200 AD) -...
• Diogenes lighted a candle in the daytime, and went round saying,
  "I am looking for a man." -- Diogenes Laertius (c...
• It takes a wise man to discover a wise man. -- Diogenes Laertius (c.
  200 AD) -- Xenophanes,...
• Xenophanes speaks thus:-- And no man knows distinctly anything,
  And no man ever will. -- Diogenes Laertius (c. 200...