Where is the word 'posterity' found in the Preamble?

The following excerpt of the Preamble is taken from the website of the National Archives. You can access a transcript via Related Links, below.

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America. (emphasis added).