Gittin 39b tells the story of a slavewoman whose master attempted to free her by giving her his hat. But this wasn’t valid because it was HIS hat. For the transfer to be valid, the object would have had to be something belonging to her.
How would this work in practice? Would the owner pass the slavewoman a hat owned by the slavewoman? Or would the slavewoman pass the master her own hat? Any of the commentators explain the mechanics?