After the tragic deaths of Nadav and Avihu, the children of Aharon, G-d
issues a command to Aharon: “Do not drink wine, nor intoxicating drink (alt.wine which is intoxicating, see Keritut 13b), you or your children, when you enter the Tent of Meeting, so you do not die; this is an eternal decree throughout your generations. To distinguish between the sacred and non-sacred, and between the impure and the pure. And [so] you may instruct the Children of Israel in all the decrees that G-d has spoken through
Moshe.” (Vayikra 10:9-11)
It is not immediately clear why this law is presented here.