I'm not sure if I've missed something, but it seems to me that a simpler way is just to go Safari>File>Save As... with Format = Page Source.

In both cases you get a local copy of the web page, not a shortcut to the live web page, so in neither case does the preview change when the web page is updated.

You are definitely correct in that the "Save As..." method works, not to mention that it is quicker and simpler.

The one difference is that the "long way" using this hint preserves more formatting, images, backgrounds, etc. while the simple and direct way that you recommend will be text only.

In both cases, the page is absolutely local. Is this hint worth the extra steps? You have to decide. I prefer the prettier, longer way myself.

Well, quick look only shows to me the html source of the .html file. Worse, it will only show me the generic webarchive icon if I save a website as a webarchive. How frustrating.