“Hard work never killed/hurt/harmed anybody/anyone” is a proverb from at least 1874. The saying means that one shouldn’t be lazy and that one should work hard; people who perform hard work in dangerous places (such as a coal mine) certainly have been killed. “Hard work never hurt any one” was described as a “common saying” in 1890.
 
“Hard work never killed anybody, but why take a chance/risk?” has been attributed to ventriloquist Edgar Bergen (1903-1978) and his dummy “Charlie McCarthy.” Charlie McCarthy supposedly said the line in a comedy routine in the 1930s, but the earliest Bergen attribution is from 1979. “Hard work never killed anyone, but why take a chance on being the first victim?” was printed in a Walter Winchell syndicated newspaper column in June 1956, attributed to the American musician Florian ZaBach (1918-2006).
   
 
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The Yale Book of Quotations
Edited by Fred R. Shapiro
New Haven, CT: Yale University Press
2006
Pg. 55:
Edgar Bergen
U.S. ventriloquist, 1903-1978
[Catchphrase of dummy “Charlie McCarthy”:]
“Hard work never killed anybody, but why take a chance?”
Quoted in Robert Byrne, The Other 637 Best Things Anybody Ever Said (1984)
Pg. 527 (Modern Proverbs):
“Hard work never hurt anyone.”
L.A. Times, 18 May 1924
 
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7 February 1874, The Lancet, pg. 214, col. 2:
THE LATE DR. PHILLIPS.
To the Editor of THE LANCET.
(...)
Now those who, like myself, know the circumstances of the case, would warn your younger readers not to draw from this a false moral as to the injurious effects of legitimate hard work. Hard work never killed anyone; there are so many hours in the day allotted to labour, and so many to rest.
 
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February 1880, Harper’s New Monthly Magazine, pg. 403:
“Ay, ay, let her work on: hard work never harmed anybody.”
 
26 December 1883, Indiana (PA) Weekly Messenger, pg. 4, col. 6:
“Hard work never killed a man; it was the fun that the men had in the intervals that killed them.”
(“Robert J. Burdette, the facetious editor of the Burlington Hawkeye”—ed.)
   
1 August 1885, New-York (NY) Daily Tribune, “Captain Ericsson at eight-two,” pg. 8, col. 5:
He is a firm believer in the saying that “hard work never killed any one, but that worry and excesses are what make men grow old.”
 
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Sanity and Insanity: with illustrations
By Charles Mercier
London: Walter Scott
1890
Pg. 265:
There is a common saying that “hard work never hurt any one,” and, like most common sayings, it expresses one half of a truth. Mere laboriousness of occupation probably never did hurt any one, provided that it was accompanied with a sufficiency of food and of sleep.
 
Google News Archive
22 June 1956, St. Petersburg (FL) Times, “Walter Winchell in New York,” pg. 15, col. 3:
Florian ZaBach’s quiery: “Hard work never killed anyone but why take a chance on being the first victim?”
 
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Joe Franklin’s Encyclopedia of Comedians
By Joe Franklin
New York, NY: Bell Pub. Co.: Distributed by Crown Publishers
1985, ©1979
Pg. 56:
Edgar Bergen: Well, Charlie, I’m sorry, but hard work never killed anybody.
Charlie: Still, there’s no use taking chances.
     
The Times of India
Into the soul of speaking tees
Bella Jaisinghani, TNN Mar 13, 2011, 06.48am IST
(...)
“They even have work experience in this field,” says the spokesperson, showing it takes its funny lines rather seriously. “Some of the popular slogans like ‘Hard work never killed anybody but why take a chance!’ were designed by this team.”