The Gemara in Menachos 39a brings that the minimum requirement from a Torah level for tzitzis is one double knot (as explained by Tosfos). Is this the absolute minimum requirement in order to wear it out in the reshus harabim?
This may seem like a clear cut gemara and the question isnt a question. However, the mefarshim do not spell out exactly what is the minimum requirement. Is there a source which says straight out what is the minimum?