“Out of the mouths of babes does often come cereal”

“Out of the mouths of babes” is a biblical saying, usually meaning that the young are honest and tell the truth. A jocular and literal meaning is:
 
“Out of the mouths of babes, often, comes cereal.”
 
The humorous twist to the saying has been cited in print since at least 1958.
 
   
Wiktionary: out of the mouths of babes
Etymology
From King James Bible, Psalms 8:2, “Out of the mouth of babes and sucklings hast thou ordained strength”. (Note that mouth is singular in the Biblical verse, and that the usage of this expression differs from the modern proverbial usage.)
Proverb
out of the mouths of babes
1. From the comments of children, who are honest and innocent, . . . (comes truth or wisdom).
           
8 May 1958, Van Nuys (CA) News, pg. 28-A, col. 5:
SURPRISE WISDOM
Out of the mouths of babes, often, comes cereal.
 
27 June 1958, Janesville (WI) Daily Gazette, “Smile for Today,” pg. 1, col. 2:
Out of the mouths of babes, often, comes cereal.
 
23 July 1982, The Times-Picayune (New Orleans, LA)< "Rib-ticklers of yesteryear" by Angus Lind, sec. 4, pg. 1, col. 1:

Out of the mouths of babes, too often, comes cereal.
 
Google Groups: rec.arts.sf-lovers
feminism in sf  
Anton E. Skaugset
6/3/91
(...)
“Out of the mouths of babes, often comes cereal.”
 
Google Groups: rec.humor
One-line aphorisms, part 3 of 4
Alan Silverstein
12/3/93
(...)
Out of the mouths of babes does often come cereal.
   
Google Groups: rec.boats 
ICW in NJ
Rick Emerson
1/5/94
(...)
Out of the mouths of babes does often come cereal.
 
Google Books
20,000 Quips & Quotes
By Evan Esar
New York, NY: Barnes & Noble Books
1995, ©1968
Pg. 56:
Out of the mouths of babes comes — cereal.
   
Google Groups: alt.toys.gi-joe
DAMN THESE TROLL WARS!
Keith Mayo
7/27/99
(...)
Just kidding, Steve. Anyone remember the saying, “Out of the mouths of babes, oft comes the truth”? I can tell you though, after raising a family, it should be, “Out of the mouths of babes, oft comes cereal”!
   
Google Books
Phillips’ Treasury of Humorous Quotations
BY Bob Phillips
Wheaton, IL: Tyndale House Publishers
2004
Pg. 22:
BABES.
Out of the mouths of babes comes . . . cereal.
 
Twitter
cowsay
‏@cowsay
Out of the mouths of babes does often come cereal.
10:39 PM - 10 Oct 2008
 
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‏@foomandoonian
‘Out of the mouths of babes does often come cereal’ - @Br3ndaBot http://is.gd/4aJv
5:01 AM - 16 Oct 2008