Aesop's Fables (1884)
238. The Stag, the Wolf and the Sheep.
A Stag asked a Sheep to lend him a measure of wheat, and said that the Wolf would be his surety. The Sheep, fearing some fraud was intended, excused herself, saying: "The Wolf is accustomed to seize what he wants, and to run off, and you, too, can quickly out-strip me in your rapid flight. How then shall I be able to find you when the day of payment comes?"
Two blacks do not make one white.
Aesop's Fables: A New Revised Version From Original Sources (translator not identified), 1884 . Illustrations by Ernest Henry Griset (1844-1907), John Tenniel (1820-1914) and Harrison Weir (1824-1906). Available online at Project Gutenberg.