After the death of Nadav and Avihu, the priests were commanded not to drink wine or any intoxicating beverage before performing the Tabernacle service. The Sages explain that it is incumbent upon a priest serving in the house of God to maintain his sobriety.

You shall not drink wine or intoxicating drink, neither you nor your sons with you, upon your entry into the Tent of Meeting (Leviticus 10:9)…Rabbi Yehuda HaLevi son of Rabbi Shalom said: In Hebrew, wine is called yayin; in Aramaic, wine is called ĥamar – which, in gematriya, totals 248 [ĥet = 8, mem = 40, resh = 200], parallel to a person’s 248 limbs. The wine enters into each and every limb, and the body grows weak, and the drinker’s rationality is undermined. Wine enters and rationality departs. Likewise, Rabbi Eliezer HaKappar taught: Wine enters and a secret emerges. Wine [yayin], which in gematriya totals seventy [yod = 10, yod = 10, nun = 50], enters, and a secret [sod], which totals seventy [samekh = 60, vav = 6, dalet = 4], emerges. Therefore, Aaron the High Priest was commanded that priests may not drink wine during the service, so that their rationality will not be undermined; rather, they must observe the Torah and maintain rationality. (Tanĥuma, Shemini)