Pharaoh lost his job force and wanted them back.  He had not counted on his ill treatment of the Hebrews resulting in their departure from Egypt. He had no one to provide bricks and put shingles on his roofs; no one to provide the hard grubby work that had brought prosperity to the Egyptian economy.  So he goes to get them back.  Pharaohs know how to use people to get what they want for themselves.  Then along came another King who wanted His people to be free.  He was not into “using them” but was all about loving them.  So this King bore them on eagles’ wings and brought them to Himself (Exodus 19:4), not to use them, but to love and free them.  Who could not serve a God like that!