That is an excellent question! I only know of two passages where God spoke directly to Aaron. In Numbers 18:8-20 (which I would encourage you to read) God spoke directly to Aaron, informing him that he and his sons would be given portions of the various offerings that the people brought. This food and drink would help to sustain them, for they labored exclusively in the Temple and had no other means of support other than what the people offered to the Lord.

Now let’s turn to Leviticus 10 and read verses 8-10, “And the LORD spoke to Aaron, saying, ‘Do not drink wine or strong drink, neither you nor your sons with you, WHEN YOU COME INTO THE TENT OF MEETING, SO THAT YOU WILL NOT DIE—it is a perpetual statute throughout your generations—and so as to make a distinction between the holy and the profane, and between the unclean and the clean’” (NASB). It is interesting to note that among the offerings mentioned in Numbers 18 that they could partake of was “the best of the fresh wine” (verse 12). But here in Leviticus the Lord prohibits them from drinking wine “when you come into the tent of meeting.” The wine and other gifts mentioned in Numbers 18:12 was only to be partaken of at home and they could share them with their family. But when it came to their priestly ministry in the Temple they were strictly forbidden to “drink wine or strong drink.” This prohibition was so serious that God added, “so that you will not die.” The priests were to have a “clear mind” so that they could “make a distinction between the holy and the profane, and between the unclean and the clean.”

These words must have gone straight to Aaron’s heart, for his two sons had just lost their lives for that very reason! Leviticus 10:1-2 says, “Now Nabad and Abihu, the sons of Aaron, took their respective firepans, and after putting fire in them, placed incense on it and OFFERED STRANGE FIRE BEFORE THE LORD, which He had not commanded them. And fire came out from the presence of the LORD and consumed them, and THEY DIED BEFORE THE LORD.” Nabad and Abihu failed to “make a distinction between the holy and the profane,” for the “strange fire” that they offered was not according to God’s Word. Leviticus 16:12 instructed the priest to “take a censer full of BURNING COALS OF FIRE FROM OFF THE ALTAR.” It seems they wanted to “do it their way,” so they refused to use “coals of fire from off the altar.” Like Cain in Genesis 4:1-5, they chose to approach God in their own way and their disobedience cost them their lives. God’s prohibition of wine or strong drink to Aaron suggests that his sons had been drinking and this clouded their judgment. Many believe this was a contributing factor in their deadly sin.

Is there a lesson for us in this? All believers in this Christian age are priests and like Aaron and his sons we are to approach God in His own prescribed way and with clarity of mind. I am reminded of what took place in the city of Corinth as recorded in 1st Corinthians 11:20, “Therefore when you meet together, it is not to eat the Lord’s Supper, for in your eating each one takes his own supper first; one is hungry and ANOTHER IS DRUNK” (NASB). Apparently believers in Corinth would have a potluck supper before they observed the Lord’s Supper and when they did, some drank too much wine. When they sat down to eat the Lord’s Supper they were DRUNK and unable to discern the seriousness of Christ’s death on the cross. God was so upset with them that we read, in verses 29-30, “For he who eats and drinks, eats and drinks judgment to himself if he does not judge the body rightly. For this reason many among you are weak and sickly, A NUMBER SLEEP.” God’s Hand of discipline came upon those saints in the form of bodily sickness, and some were even being “put to sleep” (i.e. death). Dear brother and sisters, let us take this to heart and not allow anything, whether it be alcohol or some other stimulant that serves to dull the mind and the heart, to rob us of our ability to “make a distinction between the holy and the profane.”  (209.3)  (DO)