Moses lived in the court of Egypt until he was about forty years old. He then returned to his own people, the Hebrews, and was grieved to find how they were oppressed by the Egyptians.
Once he saw an Egyptian treating a Hebrew woman very badly so he killed the man, and buried his body in the sand. The king would have put him to death for this so Moses escaped into the land of Midian, and lived there.
One day when he was feeding his flock near Horeb, God called to him out of a bush that had flames yet was not burned! And He told Moses that He had seen the sufferings of the people of Israel, and would deliver them, and bring them into the good land of Canaan, as He had promised to Abraham. He commanded Moses to go and tell Pharaoh to let the people go, that they might serve God in the wilderness.
Many miracles had to happen before Pharaoh would believe and know that He who had sent him this command was the true God, whom he and his people should worship.
Moses was very unwilling to go to Pharaoh for he thought the king would not listen to what he said. But God would have him do it, and told him to take his brother Aaron with him. So he went and when he came before the king, Pharaoh asked who the Lord was that he should obey Him. He told Moses and Aaron that they hindered the people in their work by telling them about their God wanting them to go and sacrifice to him in the wilderness. It was only because they were idle that they wished to go. Pharaoh would not let the Hebrews go! Instead he ordered that they be given more work.
The Hebrews had been making bricks of clay mixed with straw. So Pharaoh ordered that no more straw would be given to them and they would have to get the straw for themselves where they could. They had to make the same amount of bricks in the same time as when straw was found for them.
Instead of making bricks, their time was now spent looking for straw and they were beaten because the usual quantity of work was not done. The poor Hebrews were very sad, and bitterly blamed Moses and Aaron for making their condition so much worse than it had been.
God assured them through Moses, that He would certainly deliver them out of Egypt but they were so unhappy and doubtful that they would not believe.