Is “Wu Ding dreamed of a wise minister and found him among wall-builders, promoting him.” true?
attested in history
The Book of Documents (Shuo Ming) and Records of the Grand Historian (Yin Benji) record that Wu Ding dreamed of a sage, and following the dream's image, he found Fu Yue among laborers building walls at Fu Yan, and appointed him as minister.
Fu Yue
In official history, he was a wise minister discovered by King Wu Ding of Shang while building walls; in fiction, he is a symbol of a lofty sage and minister.