Prohibition on paskening halacha when one is drunk

Question

The Gemorah in Beitzah 4a says that Rav wouldn't give a drasha on Yom Tov after eating the seudah because when he would give a drasha he would be moreh halacha (give over halachic rulings) and this is ossur to do when one is drunk.

(This is based on the Gemorah there at the bottom of the page and what Rashi says.)

Is this idea (or "issur" of not paskening halachos when one is drunk -- and not only this story like someone has already pointed out) brought anywhere in Shulchan Aruch? What about in the Rambam? More importantly though I'm curious to know if this is brought anywhere in Shulchan Aruch. And if it's not, then why?

Answer 1

The Gemara (Eruvin 64a):

אמר רב יהודה אמר שמואל שתה רביעית יין אל יורה

R. Judah stated in the name of Samuel: He who has drunk a quarter of a log of wine must not give a [halachic] ruling.

The Rambam (Hil. Bias Mikdash 1:3):

וכשם שאסור לכהן להכנס למקדש מפני השכרות כך אסור לכל אדם בין כהן בין ישראל להורות כשהוא שתוי

And just as it is forbidden for a priest to enter the Temple in a state of drunkenness, so it is forbidden for every person, priest or Israelite, to give a [halachic] ruling when he is drunk.

The Rema, in the Shulchan Aruch (YD 242:13):

ויזהר כל אדם שלא יורה כשהוא שתוי יין או שאר דברים המשכרים

And every person should be careful not to issue a [halachic] ruling when he is drunk from wine or any other intoxicating substance.