Propaganda forgers embed accurate old predictions to sell false future ones.

Evidence

This obviously spurious hfiadı¯th is a typical example of a favorite technique of the forger. He begins with a “prediction” which is remarkably accurate, because it was in fact written after the events which it predicts, and having thus gained the confidence of the listener, he continues with a prediction of events yet to occur. The second, genuine prediction, as in this case, is usually wrong. — Bernard Lewis, From Babel to Dragomans, 497

Categorization

• DEFINE: Names and explains the forger’s rhetorical trick of using a genuine post-dated prediction to lend credibility to a fabricated future one.
• SEED: An essay angle: this ‘accurate prediction then false one’ confidence trick as a general pattern in modern conspiracy narratives, astrologers, and propaganda.