Here, we read the genealogies of the Levites in the land of Egypt up to the sons of Aaron. The text repeats itself, the Moses and Aaron listed in the genealogy are the same Moses and Aaron who spoke to Pharaoh. They are meant to be emphasized as Levites as if it is important.
When Jacob, Israel, issued blessings to his children (the twelve tribes), he said of Levi:
Their swords are implements of violence. Let my soul not enter into their council; Let not my glory be united with their assembly; Because in their anger they slew men, And in their self-will they lamed oxen. Cursed be their anger, for it is fierce; And their wrath, for it is cruel. I will disperse them in Jacob, And scatter them in Israel.
Genesis 49:5b-7 NASB 95
We have already seen Moses kill an Egyptian in his anger (Exodus 2:12). Ironically, it is the Levites who will be made the priests and prophets of Israel (cf. Exodus 7:1; 28:1). So, in the narrative, we are given the nature and fate of the Levite tribe—angry, violent, and destined not to have their own land. After we already know this about the Levites, God then prepares to make them priests and prophets within Israel. It is why He chooses Moses, who on one hand is bold enough to murder an Egyptian and on another tells God he is unskilled in speech to excuse himself from talking to Pharaoh.
Fast-forward to the New Testament, and you will recall the conversion story of Paul (Acts 9:1ff). Paul persecuted Christians, even unto death, and God chose him to take the gospel to the gentiles. When He called Abraham out of Ur, Abraham was an idolater who did not know God. When He chose David, David was a liar, idolater, and playboy who always struggled against his sin. By design and by God’s will, the priestly tribe in Israel will constantly be plagued by its own tendency toward violence, anger, wrath, and dispersion among the tribes. Why would God do this on purpose?
Scripture explicitly states that a thorn is given, a messenger of Satan, in order to keep a person from exalting himself (2 Corinthians 12:7). For the Levites, their thorn is made obvious to everyone. They cannot make lasting intercession because they are not perfect and do not serve as priests forever (cf. Hebrews 7:23ff). The priests who make sacrifices quite literally have blood on their hands. Their thorn is meant to keep them humble and to keep people from trusting in them for salvation. They are merely a shadow of the perfect priest to come—Jesus.
This is why pastors also have thorns in their sides—sins they can’t seem to shake. It is different for each one. We often criticize them because they are not perfect, but God sovereignly places thorns on purpose. A pastor who loves God hates his sin, and it plagues him. It is meant to keep him from boasting. It is not hypocritical to struggle against sin. It is hypocritical to pretend it isn’t there and condemn others for sin when it is also in our own lives. This is why a good pastor will be humble, not exalting himself or wearing a mask that keeps others from seeing his humanity. Instead, we exalt Christ as the only one who can save. When our thorns stab us, we remember our humble places. There is no room in the kingdom of God for any true king or intercessor other than God. For priests or pastors to do ministry in any way that exalts them rather than Christ is blasphemy, and there are many who need to recognize this truth in our own day—a day that “high church” culture and invented religions still exalt people rather than Christ as our only true prophet, priest, and king forever.