That’s right!  God made sure that the land of Goshen, where Israel was staying, remained free of the plagues.  There was one exception, however.  After nine plagues, God had a final judgment that would definitely free the Hebrews.  One night, the firstborn of every house, Hebrew and Egyptian, died unless that house did something specific.  What was it?

-Walk around the walls seven times-

-Accept Jesus as their Savior-

-Stay inside all night-

-I got you again.  The picture is the answer.  Put the blood of a lamb on the doorposts-