Exodus 32:19 (NIV)
When Moses approached the camp and saw the calf and the dancing, his anger burned and he threw the tablets out of his hands, breaking them to pieces at the foot of the mountain.
Moses was born during a tumultuous time. A new king had been installed to oversee the affairs of Egypt, one who had no care or concern about the great deeds of Joseph, who had saved the entire country when he prophesied of a great famine that was approaching. Joseph kept the Egyptian people from starvation when he had the foresight to set aside food to feed not only the Egyptians but also people from other lands.
However, this new Pharaoh was more concerned about his legacy as a leader than returning favors for past good deeds accomplished under a different ruler. Thus, he decided the best way to deal with the Hebrew people, who were multiplying faster than his own, would be to kill their firstborn sons.
The honor of delivering his people from 400 years of slavery was given to Moses at the burning bush. God chose him and worked many miracles through him, including bringing down a tablet from the mountain with the Ten Commandments, written out by God himself. But Moses had a temper. The first time we hear of it is when he killed an Egyptian for dealing too harshly with a fellow Hebrew. We see it again when in anger he threw the first tablets of stone to the ground, breaking them, because the Hebrews thought it would be a good idea to make a golden calf and worship it while Moses was receiving the Ten Commandments. We see the last of his temper when the Hebrews were thirsting in the desert, and God told him to speak to the rock and water would come out. Instead, in anger Moses hit the rock.
Yet this is the man who God used to deliver a people, complete the first tabernacle, and establish a way of worship for a people who had long ago forgotten to whom they belonged. While that temper of Moses’s kept him from going into the Promised Land, God rewarded his work by taking him to Canaan to get a glimpse of it.