Well, i was not able to find a proper source for the first one (maybe i'm retarded) but it seems that this "quote" and the other version of it i heard: "A lie repeated 1000 times becomes the truth" (which actually bares a lot of truth) is also hard to verify. I probably downloaded the image from old voat and i easily found the full, transcripted speech for the second one before i posted it.
[ + ] Antiliberalsociety
[ - ] Antiliberalsociety 2 points 4 yearsApr 28, 2021 06:14:40 ago (+2/-0)
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[ + ] AlfonsHilter
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[ + ] chrimony
[ - ] chrimony 1 point 4 yearsApr 27, 2021 22:16:02 ago (+1/-0)
"The astonishing thing is that Mr. Churchill, a genuine John Bull, holds to his lies, and in fact repeats them until he himself believes them."
"The English follow the principle that when one lies, one should lie big, and stick to it."
https://research.calvin.edu/german-propaganda-archive/goeb29.htm