This is a chinese letter written 1000 years ago
It is about trade between collectors
Collector Mi Fu (1051-1107 AD)was intersted in a vintage letter written by Wang Xianzhi (344-386 AD )which was owned by collector Liu
He write Liu a letter to offer several vintage letters and paints for trade
Unfortunately , after the letter was sent, Mi found one of the offered was not in his hand. It is borrowed by another collector.
He immediately wrote this letter for explaination and offered another one to swap the missed one
The letter begans as
"How about the letter written by Huai Su (737–799 AD)..."