Easy Question (Din in Shulchan Aruch)

When are you required to fast for 5 days ?

The Rema (Y.D. 123 : 26) quotes a Teshuvas Harosh, "If someone

drank Yayin Nesech Beshogeg, he should fast 5 days, because It says

5* times Gefen in Chumash."

*There are actually  7 times “Gefen”in the Torah. Some answer

We exclude 2 which are in Mishna Torah (Devarim)

The Orach Mishor argues and claims it says “in CHUMASH” ,

 Mishna Torah is part of Chumash.

The Bach says it’s referring to the five times it says

Gefen at the story of the Sar Hamashkim. This is also incorrect

It only says twice Gefen at the Sar Hamashkim.

The O.M. corrects the Girsa in the Bach, to say except for

the 2 at the Sar Hamashkim.

The Chasam Sofer has a long explanation why we exclude

The two times it says Gefen at the Sar Hamashkim.

(The two Gefens are referring to Yerushalayim shel Maloh

&Matoh)