The elder brother of Moses (by 3 years) and Miriam. He grew up as a slave in Egypt, unlike Moses who grew up in the palace. He bore the yoke of Pharaoh while Moses was in Midian.
He was born into the tribe of Levi, a tribe known for zeal and violence (Genesis 49). God would transform this violent zeal into holy jealousy for the Tabernacle.
He was formed by "Staying." While Moses fled, Aaron stayed with the suffering people. He knew their pain intimately. This made him a compassionate priest, but also susceptible to their pressure.