Predict git commit id and commit a file which contains that commit id

Question

How to do something like this:

1. Create a with following content:

   $ cat testfile.txt
   This file will be committed with this id: 83b90a07620ef578450c40a6d38bacc42de7ad2d

2. Commit testfile.txt
   $ git add testfile.txt
   $ git commit -m 'Thank you'

3. Execute git log to verify predicted commit id:
   $ git log
   commit 83b90a07620ef578450c40a6d38bacc42de7ad2d
   Author: rohit01 <*@gmail.com>
   Date: Fri Feb 21 23:46:52 2014 +0530
   

Basically, predict the next git commit id and commit a file which contains that commit id.

Answer 1

That is cryptographically impossible.

The git commit ID is an SHA1 hash of the contents of the commit.
Any change you make in the commit will also affect the ID.