In Numbers 12, the Lord is angry with Aaron and Miriam for speaking against Moses. Miriam and Aaron had become jealous of Moses because of his special relationship with God. They thought that they should have the same level of authority as Moses, and so they spoke against him.
The Lord calls them out for their behavior and punishes Miriam with leprosy. Aaron pleads for her forgiveness, and the Lord relents and heals her. This is a reminder that God is a God of mercy and grace, and that He will forgive us when we repent.
The Lord also makes it clear that Moses is His chosen leader and that no one should speak against him. This is a reminder that God has a plan and a purpose for each of us, and that we should not try to usurp His authority.
Finally, the Lord commands Moses, Aaron, and Miriam to go to the Tabernacle. This is a reminder that we should always seek God's presence and guidance in our lives. We should seek Him out in His house, the Tabernacle, and in His Word.
In Numbers 12, we see God's mercy and grace, His plan and purpose for each of us, and His desire for us to seek Him out. We should take these lessons to heart and strive to live our lives in obedience to Him.