From the ArcaMax Publishing, Jokes Newsletter:
http://www.arcamax.com/news/jokes/s-573494-942273
The children were lined up in the cafeteria of a Catholic elementary
school for lunch.
At the head of the table was a large pile of apples.
The nun made a note, and posted on the apple tray: "Take only ONE. God
is watching." Moving further along the lunch line, at the other end of
the table was a large pile of chocolate chip cookies.
A child had written a note, "Take all You want. God is watching the
apples!"