There was a man who had a copy of the Wakan Roeishu (poetry collection) which was reputed to have been copied by Ono no Dofu (who died
in 966 at the age of 72).
Someone said to him, "Although it has been inherited by you as such, for a book which was compiled by Shijo Dai-nagon (who was born in 966) to have been transcribed by Dofu would be an anachronism. Thus, you must doubt its authenticity."
But the man replied, "For that very reason it must be the rarest thing in the world." And he treasured it more than ever.
Tsure-zure-gusa ("Essays in Idleness")