12:1 Miriam and Aaron (Moses' siblings) exemplify humanity's sometimes contemptuous nature in this chapter. As with all family matters, we cannot entirely understand the reasons behind the argument in this chapter.
Miriam and Aaron express anger with Moses for marrying an Ethopian woman. Ethiopia as it was then is not the Ethiopia we know now. Moses actually marries a woman from Cush. The location of Cush is disputed but could be somewhere in or near the Arabian Peninsula.
We know that Moses is married to Zipporah but because so much time has passed, it is possible that Zipporah is no longer alive on earth. The true root of Miriam and Aaron's anger, however, is expressed in the following verses.
12:2 They're jealous of Moses' relationship with God.
12:3 It is pointed out in this verse that Moses is extremely humble. Having followed Moses' life for quite some time now, we have observed Moses' humility. We know that he has never flaunted his work or become arrogant with power. Miriam and Aaron's jealous-anger toward Moses is undeserved.
Jealousy is a dangerous expression and emotion. It causes destruction and therefore God cautions us against it: Exodus 20:17. Jealousy causes Miriam and Aaron to lose sight of the broader picture and create animosity in a place of peace.
12:4-5 God approaches the situation as the Parent that He is. He calls the three siblings together in order to hear a lesson from Him.
12:6-8 God explains to Miriam and Aaron that Moses' direct and personal connection with God means that God knows Moses' heart, intentions and actions. God basically says: Frankly, I am surprised you would even approach Moses in contempt as if I am not doing my job of keeping him honest and fair.
It isn't that Moses can do no wrong. It's that it is God's business and Moses' business about any wrongdoing he might be guilty of. Of course we all have people in our lives (often family) who keep us in line with their observations of our behavior. The problem is that Miriam and Aaron were not concerned about Moses' wellbeing, they were just jealous of him and expressing it in ugly ways.
12:9-12 Aaron and Miriam receive a glimpse of what life is like when a person does not allow God's authority to be in control. Miriam becomes leprous (a common and treacherous ailment of the time). Sometimes reality shocks us back into line. Moses' work for God enabled tens of thousands (including his own family) to receive healing from God. Ugly jealously against Moses is an expression of ingratitude for all that his hard work has earned them.
12:13 Moses pleads to God: Please heal here, O God, I pray! Even though his brother and sister were essentially working to usurp him and unfairly damage his character, Moses' kind and gentle nature remains unchanged. He pleads and prays for healing for his sister. Moses' behavior also reminds us that he is a kind and just man, if did take a wife, we can guess that was for an honorable reason.
12:14-16 Miriam's reality check lasts for seven days and then she receives healing. We all go through seasons of reality-checks and they are difficult and sometimes painful... but they are also opportunities for growth. God's tough-love in action helps us to grow in character.
