On the flip side, if they were Nazis, if they just hated us and wanted to be rid of us: Why try to stop us from leaving? Why enslave us at all; why not just kill us?
Other nations can receive blessing also; it will be through Abraham and his nation. Israel is the central source of blessing in the world.
What could Egypt do about it? The right thing or the wrong thing. At first, Egypt tried to draw close to Israel, to do as much kindness for them as possible. Eventually, however, they decided to try to take what they wanted without earning it; to get the blessing by controlling its source.
(from R’ Michoel Reach, jewishanswers.org)