סימן ק סעיף ג

קֹדֶם נְשִׂיאַת כַּפַּיִם, לֹא יִשְׁתֶּה הַכֹּהֵן לֹא יַיִן וְלֹא שְׁאָר מַשְׁקֶה מִמַּשְׁקִים הַמְשַׁכְּרִין. וְאִם לִבּוֹ חָלוּשׁ וְרוֹצֶה לֶאֱכוֹל פַּת כִּיסְנִין קֹדֶם מוּסָף, יִשְׁמַע קִדּוּשׁ מֵאַחֵר (עַיֵן לְעֵיל סִימָן ע"ז סָעִיף ט"ו).

Before pronouncing the Birkas Kohanim the kohein may not drink¹²He is forbidden to drink a revi’is of undiluted wine without pausing. However, if he drinks more than a revi’is of wine, even if diluted with water, and even if he paused many times while drinking, he may not pronounce the priestly blessings. (Shulchan Aruch 128:38) wine or any other intoxicating¹³Magein Avraham 128:55 rules if he drank other intoxicating beverages, he may duchan so long as he is not stone drunk; even if he is not sober enough to speak before a king. The Eliyahu Rabbah and Derech Hachaim rule that he must be sober enough to speak before a king (as by tefillah). Taz rules that he may not drink any amount of an intoxicating beverage before he duchans, because the minumum of a revi’is applies only to wine. beverage. And if he feels faint, and wants to eat some cake before musaf, he should listen to someone else's kiddush.

תנא דבי אליהו כל השונה הלכות בכל יום מובטח לו שהוא בן העולם הבא שנאמר הליכות עולם לו אל תקרי הליכות אלא הלכות (נדה ע"ג.)