The Interpretation of Dreams by Sigmund Freud Chapter 3 Page 15

The impression left is that the formation of obscure dreams proceeds as if a person had something to say which must be agreeable for another person upon whom he is dependent to hear. It is by the use of this image that we figure to ourselves the conception of the dream distortion and of the censorship, and ventured to crystallize our impression in a rather crude, but at least definite, psychological theory.

Whatever explanation the future may offer of these first and second procedures, we shall expect a confirmation of our correlate that the second procedure commands the entrance to consciousness, and can exclude the first from consciousness.

Once the sleeping state overcome, the censorship resumes complete sway, and is now able to revoke that which was granted in a moment of weakness.