
“Whoever tells a lie is not pure of heart, and such a person can not cook a clean soup.”
To Mme. Streicher, in 1817, or 1818, after having dismissed an otherwise good housekeeper because she had told a falsehood to spare his feelings. in Beethoven: the Man and the Artist, as Revealed in his own Words http://www.fullbooks.com/Beethoven-the-Man-and-the-Artist-as-Revealed2.html by Ludwig van Beethoven, edited by Friedrich Kerst
Attributed
Variant: Anyone who tells a lie has not a pure heart, and cannot make a good soup.