Hmmmm...1st word has to be ho(e)p; no other garden tool is short enough to fit in there! I could only come up with "hop on", but that didn't explain "stone"; looked up all 2letter words and only other ones that made a bit of sense are "in" or "it"; so pit = stone?
So "hop it" ? Brand new to me.
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I'm just an imagination of your figment!