12:1 Miriam and Aaron spoke against Moses because he married an Ethiopian woman. It was odd that his brother and sister gave him so much criticism. You would think that they would support Moses' decision and have faith in him. It's because of the woman that he had married that caused his siblings to be upset. Moses' wife (Zipporah) was the daughter of Midian. Moses' siblings kept bad mouthing him and his wife because of her appearance. Probably because she was negro or had a dark complexion.
12:2 Moses "goes about acting as if he is the only one the Lord speaks through," accusing Moses of pride. God had spoken to Miriam and Aaron before but he did not give them the authority to rule. God hears everything, and he hears truth not to appearance.
12:3 Moses then answers to the people and says, "Do not be afraid. Stand firm and you will see the deliverance the LORD will bring you Today.
12:4 and the lord spake suddenly to Moses, and Aaron, and Miriam. In order to not get people angry we had to alert others that Moses took matters into his own hands and as soon as Miriam and Aaron uttered their speech against Moses, the Lord had spoken to them.
12:5 Then, the Lord came down to something that's called a pillar of cloud which means that you are in the hands of the Lord and then the Lord stood in the door of tabernacle where he set up the tribunal, then called for Aaron and Miriam to join him and hear what he had to say to them because of the issue that occurred earlier and Moses kept his distance so he wouldn't be caught in the middle. Lastly, the both of them stepped up and stood before the Lord.
One thing that the both of us have learned is that people will have more than you in life. Whether that's the newest iPhone or the newest style of clothing. If you are jealous, it could have a negative consequence just like Aaron and Miriam had a negative consequence by talking about Moses' wife. It could come off as rude even though you might not mean it in that way. We could apply this to our own life by complimenting people on their clothing or their phone by trying not to show that we might be jealous.