The injunction against kohanim drinking wine

Summary: with the connection, according to Bechor Shor, of it being something served to mourners, rather than it being the sin for which Nadav and Avihu were guilty.

Post: Immediately after the death of Nadav and Avihu, there is a commandment that kohanim not enter into the Ohel Moed while intoxicated:

8. And the Lord spoke to Aaron, saying,		ח. וַיְדַבֵּר ה אֶל אַהֲרֹן לֵאמֹר:
9. Do not drink wine that will lead to intoxication, neither you nor your sons with you, when you go into the Tent of Meeting, so that you shall not die. [This is] an eternal statute for your generations,		ט. יַיִן וְשֵׁכָר אַל תֵּשְׁתְּ אַתָּה וּבָנֶיךָ אִתָּךְ בְּבֹאֲכֶם אֶל אֹהֶל מוֹעֵד וְלֹא תָמֻתוּ חֻקַּת עוֹלָם לְדֹרֹתֵיכֶם:

According to one midrash, cited by Rashi, this was because Nadav and Avihu had been intoxicated, and this had been their sin:

And fire went forth: Rabbi Eliezer says: Aaron’s sons died only because they rendered halachic decisions in the presence of Moses, their teacher. Rabbi Ishmael says: [They died because] they had entered the sanctuary after having drunk wine. The proof is that after their death, [Scripture] admonished the survivors that they may not enter the sanctuary after having drunk wine. This is analogous to a king who had a faithful attendant. [When he found him standing at tavern entrances, he severed his head in silence and appointed another attendant in his place. We would not know why he put the first to death, but for his enjoining the second thus, “You must not enter the doorway of taverns,” from which we know that for such a reason he had put the first one to death. Thus [it is said], “And fire went forth from before the Lord and consumed them, and they died before the Lord.” But we would not know why they [Nadab and Abihu] died, but for His commanding Aaron, “Do not drink wine that will lead to intoxication.” We know from this that they died precisely on account of the wine. For this reason Scripture showed love to Aaron by directing the divine utterance to him alone, thus, “Do not drink wine that will lead to intoxication,”] as recounted in Vayikra Rabbah (12:1).

ותצא אש: רבי אליעזר אומר לא מתו בני אהרן אלא על ידי שהורו הלכה בפני משה רבן. רבי ישמעאל אומר שתויי יין נכנסו למקדש, תדע שאחר מיתתן הזהיר הנותרים שלא יכנסו שתויי יין למקדש. משל למלך, שהיה לו בן בית וכו', כדאיתא בויקרא רבה:

But R' Yosef Bechor Shor gives an alternate connection to the unfortunate incident:

"Wine and mead do not drink -- even though they give wine and mean to other mourners, as is written {Mishlei 31:6}:

ו  תְּנוּ-שֵׁכָר לְאוֹבֵד;    וְיַיִן, לְמָרֵי נָפֶשׁ.	6 Give strong drink unto him that is ready to perish, and wine unto the bitter in soul;
ז  יִשְׁתֶּה, וְיִשְׁכַּח רִישׁוֹ;    וַעֲמָלוֹ, לֹא יִזְכָּר-עוֹד.	7 Let him drink, and forget his poverty, and remember his misery no more. {P}

Even so, you {=Aharon} and your sons shall not drink, for you are forbidden when you enter into the Ohel Moed, and there is in it liability to death."

I wonder if by separating yayin and shechar here, Bechor Shor is also disagreeing with Rashi/Chazal and agreeing with Ibn Ezra as to the identity of yayin veshechar. Thus, Rashi wrote:

wine that will lead to intoxication: Heb. יַיִן וְשֵׁכָר. [שֵׁכָר does not mean other strong drink,] but wine in a manner that leads to intoxication" [namely, sufficient wine to cause intoxication, undiluted, and drunk without interruption]. — [Torath Kohanim 10:35]

יין ושכר: יין דרך שכרותו:

Thus, one entity which is yayin and shechar, intoxicating. While Ibn Ezra identifies it as:

ושכר -העשוי ממין חטה או דבש או תמרים

That which is made from a species of wheat, honey, or dates.