Exodus 20:2

I am the Lord, thy God, which have brought thee out of the land of Egypt, out of the house of bondage. That was the Lord's solemn introduction to the legislation on Mount Sinai, a reminder of the wonderful deliverance which He had wrought when He led forth His people out of the land of Egypt, where they had virtually been slaves. Note that the Decalog, as here given, was intended for the children of Israel and applied its principles to the circumstances under which they lived, with a form of government every detail of which was fixed by the Lord.