“Man cannot live by bread alone; he must have peanut butter”

“Man doth not live by bread alone” and “Man shall not live by bread alone” are passages in the Bible.  “Man cannot live by bread alone; he must have peanut butter” means simply that something should go between the slices of bread. The saying has been improbably credited ot U.S. President James A. Garfield (1831-1881), but “peanut butter” didn’t exist during his lifetime. Comedian Bill Cosby has also been given credit; while he might have said it, he almost certainly didn’t coin it.
 
“Man cannot live by bread alone; he must have peanut butter” has been cited in print since December 1964, when the Associated Press reported it on a sign in a St. Louis (MO) supermarket.
   
 
Answers.com
Proverbs: Man cannot live by bread alone
With allusion to two biblical passages (both AV): deuteronomy viii. 3 Man doth not live by bread only, but by every word that proceedeth out of the mouth of the Lord doth man live; matthew iv. 4 Man shall not live by bread alone.
     
16 December 1964, Cumberland (MD) Evening Times, “Something Extra,” pg. 10, col. 3:
ST. LOUIS, MO. (AP)—A sign in a local supermarket proclaims: “man cannot live by bread alone; he must have peanut butter, 79 cents a jar.”
   
Google Books
Pacific Oil World
Volume 59
Petroleum Publishers
1966
Pg. 28: 
In supermarket: “Man cannot live by bread alone — he must have peanut butter. Only 79c a jar.”
 
Google Books
PTM
Volume 70
Piano Trade Publishing
1973
Pg. 25:
Remember, as the comedian Brother Dave Gardner put it, “Man cannot live by bread alone — he must have peanut butter!”
   
12 March 1990, St. Louis (MO) Post-Dispatch, pg. 1F:
Bill Cosby sums it up this way: ‘‘Man cannot live by bread alone. He must have peanut butter.’‘
 
Google Books
Ice Cream!:
Delicious ice creams for all occasions
By Pippa Cuthbert and Lindsay Cameron Wilson
London: New Holland
2005
Pg. 132:
The American actor Bill Cosby once said ‘man cannot live by bread alone, he must have peanut butter’.
 
Google Books
If ignorance is bliss, why aren’t there more happy people?:
Smart quotes for dumb times
By John Lloyd and John Mitchinson
New York, NY: Harmony Books
2008
Pg. 116:
Man cannot live by bread alone; he must have peanut butter.
JAMES A. GARFIELD
 
Naturally D’Lish
Monday, February 15, 2010
“Man Cannot Live By Bread Alone…”
“He Must Also Have Peanut Butter.” ~President James A. Garfield