I have not told half of what I saw.

On his death-bed, when urged to retract "some of the seemingly incredible statements he made in his book", as quoted in The travels of Marco Polo, the Venetian (London: J. M. Dent, 1926), p. xxiv. Quote in Italian from Imago mundi seu Chronica (c. 1330) by Jacopo d'Acqui, as reported in the bibliographic note to Marco Polo: Storia del mercante che capì la Cina (2009) by Vito Bianchi