What about taking Brandon's idea but keeping them close to eachother and short:
[edit] [s]
or
[edit | s]
It's as short as you can get while keeping the primacy of 'edit'. Also, the letter 's' makes sense for either 'source' or 'section'.
No idea what basic usability/design conventions that breaks, but I imagine 2 small icons won't be much more intuitive than a letter with a tooltip.
Alternately, with Erik's idea:
[edit] [<>]
In any case, as a reader, and even just as an editor I think the distraction of the animation makes the clutter tradeoff worth making.
Cheers,
Jake Orlowitz Wikipedia: Ocaasi http://enwp.org/User:Ocaasi