Stab
You hit your head on a tree and a knife falls out and stabs you. Ow! What the heck?! What was a knife doing in that tree?
Imagine the pain and confusion of being stabbed by a violent tree. You hit your head on the tree again, as if to test it, and again a knife falls out and stabs you. Oh, so it's a stabbing tree, is it? That does it!
し
さ
None
There's nothing more dangerous than a tree that likes to stab, so you get your saw (さ) and start to saw it down. Trees that stab get sawed!
Feel the grain of the saw's wooden handle in your bare hand. As the saw bites into tree bark, a retaliatory rain of knives comes stabbing down around you. But you don't even flinch. You will saw this stabbing tree down.