Great question. This site lacks credibility but does offer a few things - including Ptolemy - on which we can hang our hat. It is not a clear link to wishing, but it is of interest.

This site has more credibility, but unfortunately, that probably means its vague answer about origins is closer to the mark. I've not seen an analysis of the question of the origin of this wishing practice, and like so many minor folk practices, it can be extremely difficult to track in the historical record, let alone to determine the origin of the practice.