Where can I download Firefox 4.0?

Not the revolutionary 4.0.1 but SEVERAL.0.

File Hippo has each of the older reproductions.

http://www.filehippo.com/download_firefox/

http://www.mozilla.com/en-US/firefox/fx/
http://www.getfirefox.net/

I recognize the first one can be trusted, but I’m confused if it can be 4.0..seeing that all the idea says is definitely 4.
Confused if the next one is really a trusted web site, so acquire at your individual risk…