There was again that sense of needing to look away, and there on his bed appeared a...
bigger rock!
Well, it was quite bigger, more like a boulder. Jon's bed sagged underneath the weight. It was obviously too heavy for Jon to lift, so he said "I wish that the boulder was very light."
Jon tried to lift the boulder, and it was as light as a feather, as if it were made out of polystyrene. But it was still unweildy, so Jon said; "I wish that whenever I made a wish with the wishing rock, it would send the wish through to this large boulder and the boulder would carry out the wish."
The rocks glowed.
Now, thought Jon, to try out the rock. "I wish..."