What happened in Egypt was the institution of the Passover, and the lamb whose blood was applied on the lintel and doorposts was a shadow of Jesus Christ,

Passover means exemption, indemnity or impunity,

To apply is to use, exercise, carry out or to practice,

Israelites had to carry out what God had said in order to be safe,

This mainly illustrates that when we hear the word we must put it to use to be effective.