use git cat-file -p SHA1 to view the file content of the blob.

The content of the file is this:

blob XXX NULL Content

ex:

a.txt contain Hello World

The Content of the SHA-1 is:

blob 11\000Hello World and this strign is then GZipped

use git cat-file -p SHA1 to view the file content of the blob.

The content of the file is this: blob XXX NULL Content

ex:

a.txt contain Hello World

The Content of the SHA-1 is:

blob 11\000Hello World and this strign is then GZipped

If you are on unix u can use this to deflate the content:
perl -MCompress::Zlib -e 'undef $/; print uncompress(<>)'