The Promised Land was first made to Abraham and was renewed to his son Isaac and later to Jacob. It was to be given to the Israelites after Moses had led them from the bondage of Egypt. Moses was the son of an Israelite but was adopted by Pharaoh's daughter and raised as a royal child in the palace. He was educated about God and his promises to the children of Israelites. By his real mother who asked to take care of him.
When Moses was an adult, he found two people fighting, an Egyptian and an Israelite. He killed the Israelite to prove his loyalty to the Egyptians and due to this immoral act; he went into hiding but had his faith in God. He was later called by God to deliver the Israelites from slavery. Moses rejected the call giving a reason that he was not a good orator, but God insisted1. When he finally went to see the pharaoh, he refused to let go of the slaves as the Egyptians had provided all the services to their masters. Pharaoh was adamant about his decision of letting the Israelites go, and God punished him with the ten calamities that softened his heart and let them leave.
The Israelites were difficult to persuade to leave Egypt as they had lived all their lives there. Moreover, Moses had a hard time leading them out. It was a difficult mission for Moses to lead the rowdy ex-slaves into the wilderness as they had no rules to guide them. God saw this and gave Moses the Ten Commandments after fasting for forty days at Mt Sinai. However, as Moses was climbing down the mountain, he found the Israelites doing all sorts of immoral things and worshipping idols that made him angry and dropped and broke the commandments that were written on stone pillars.
Moses was very angry and destroyed the idol. He went back to the mountain to repent on behalf of the children of Israelites and after forty days, God allowed him to engrave the commandments on rock tablets.