THE GREAT WONDER- NO WONDER

The Mechaber in Shulchan Aruch (O. Ch. 580) lists additional fast days.

One of the fast days is on the 9^th day in Teves. “It is unknown what

Tzoroh happened on that day”.

The ט"ז writes" תימה גדולה  (It's a great wonder) that the Bais Yosef

doesn't know what happened that day. In our Selichos (Ezkero Motzok)

it is written that Ezra Hasofer died on the 9^th of the month".

It is interesting, this Piyut is said, only by Ashkenazim. The Sefardim

say the Piyut “Sha’a Elyon” and the Piyut “Yoshev Bashomayim”.

In both of these Piyutim, it is mentioned that Ezra Hasofer died on the

10^th of Teves.

The Mechaber, being  Sefardi didn't say the Piyut Ezkero Motzok.

He said instead the other two Piyutim that states Ezra was niftar 

on the 10^th and therefore there shouldn't be a wonder why he 

didn’t know what happened on the 9^th of Teves. אמבצי

Ashkenaz