The need for rescue was clearly related to the Israelites' condition. The Egyptians forced the people of Israel to work without mercy (1:13). It was also related to promises God had made to the patriarchs years earlier.
The Lord had promised Abraham that his descendants would become a great nation, living freely in the land of Canaan. At this time, Abraham's descendants were slaves in Egypt under a pharaoh who wanted to destroy them as a people. God would have to rescue them to fulfill his promises.