Mwe Ngoyo was the queen mother, the ancestral root of Ngoyo, shared by Ngoyo, Kakongo, and Loango. She often entered into trance states. One day, during one such trance, an entity appeared before her in human form, an apparition she believed to be Nzambi A Mpungu (the supreme god). But in reality, it was an earth spirit, a bisimbi ba nsi.
This spirit showed her images, symbols, drawings, and motifs. Mwe Ngoyo realized that these symbols represented ideas. The simbi ba nsi taught her the meaning of each symbol by showing her several drawings and explaining that these objects could be used to express thoughts and concepts. (They are known as bakisi ba nsi.)
When she returned to herself, Mwe Ngoyo summoned her advisors and asked them to find the best sculptor in the kingdom. After sharing her vision with him, the sculptor carried out her request.
He presented his work; she approved it and showed it to her people. The inhabitants of Ngoyo appreciated it in turn and, from that moment on, they developed this mode of expression. This is how a great number of proverbs and thoughts have since been illustrated using conventional symbols.