"Moses was a very humble man, more humble than anyone else on the face of the earth." - Numbers 12:3
Moses' relationship with his sister, Miriam, and brother, Aaron, was complicated. Miriam had been used by God to rescue baby Moses from slaughter, and Aaron had been Moses' mouthpiece when speaking to the king of Egypt (see Exodus 1-3). Doubtless the three loved each other. Yet sibling rivalry apparently began to gnaw at Miriam and Aaron: they didn't like Moses' foreign wife, and they seemed jealous of Moses' position as God's special prophet. They began to talk against Moses: "Hasn't [God] also spoken through us?"
Moses' humility and love were evident in that he didn't hold a grudge against his brother and sister for undercutting him. He hadn't been looking for prestige when God chose him to be the leader of Israel. He hadn't even wanted the job! He also knew that his privilege of speaking face to face with God was completely because of God's grace. He didn't become proud. Like Jesus, Moses was an intercessor. He pleaded with God for Miriam's healing.
Moses' humility was precisely what made him a great servant of God. As Jesus said, "The greatest among you will be your servant" (Matthew 23:11).
As Colossians 3:12 says, "Clothe yourselves with compassion, kindness, humility, gentleness and patience." We know from Jesus' and Moses' examples that humility covers a multitude of sins, and it brings healing to what would otherwise be ruined relationships.