Hi Phil and Marggi -
Dreams are strange, aren't they? :-)
It's an interesting dream. In the first part of it, if I understand your dream report correctly, you actually are conversing with your three old, as if you were speaking to an adult, and you both are agreeing that - because he is in danger - that you should cut off his feet.
I think every parent can sympathize with the spirit of your intent. Three year olds always are one step step away from some sort of serious injury - as they put their hands into disposals, pick up broken glass, run near the top of a stairs, etc.
It would be nice if we could speak to our children as adults - and if they would listen and comprehend us. But three year olds aren't adults, as your dream seems to remind you. You have an adult conversation for an instant - in which you both agree that he should not run around as much (the amputation) because it is a threat to his safety (the outside force) - but then suddenly he reverts to his real age - and begins to respond as any three year old would - screaming and running away.
It is significant that, when you suddenly are confronted in the dream with a literal interpretation of your actions - represented by your friends treating you with disgust - you immediately recognize the symbolic nature of your intent. There is no blood - and your baby boy is running. Despite the appearances - you are aware that you did not intend to injure your son.
Given the information you have supplied me, I sincerely believe that your dream simply represents a desire on your part to restrain your boy - to protect him from running around and getting into trouble - and also reflects your desire (attempts) to try to communicate with him on an adult level - that are of course destined to only partial success. I realize the "language" that the dream chooses to speak in - amputation representing restraint - is a bit graphic and offensive - but I suggest that this type of symbology in dreams is common and should be understood for what it is - as metaphor and nothing else. In no way does this symbology reflect any desire on your behalf to harm your son. To the contrary - you are attempting to protect him.