What is the preface to the ten commandments?

The preface to the ten commandments is in these words; I am the Lord your God.” 

Exodus 20:2 (NASB)
“I am the LORD your God, who brought you out of the land of Egypt, out of the house of slavery.

It was Israel whom the Lord took out of bondage in Egypt; therefore, the latter clause “who brought you out of the land of Egypt” is specific to the history of Israel but the former, “I am the LORD your God” is applicable to all of mankind, for the LORD is creator of all and he took us from the house of slavery. 

John 8:34-36 (NASB)
Jesus answered them, “Truly, truly, I say to you, everyone who commits sin is the slave of sin. The slave does not remain in the house forever; the son does remain forever. So if the Son makes you free, you will be free indeed.”