Book of Numbers
In Hebrew, the book is called Bemidbar (בַּמִּדְבָּר), which means 'in the desert.' This is because Moses and the Hebrew people wandered in the Egyptian desert for 40 years, fleeing from the pharaoh after more than 400 years of slavery. When the people found that Israel was filled with strong and powerful people of other races, they became scared and rebelled against God and Moses. As a result of their bad behavior, therefore, God punished them by making the Israelites travel forty years before they could settle in Israel, the promised land. This was also so that the next generation of Israelites would enter the promised land, following the death of the previous, badly-behaved generation.