The source given is volume 13 of the Muqarnas journal. It is not available online for free, but it can be found is in this article by Nasser Rabbat.
I cannot find any Jewish sources for this assertion. I did find it mentioned in passing in this Arabic article. (People also claim that Maimonides lectured at the University of al-Qarawiyyin in Fez, Morocco.)
Does anyone know the source for this? It doesn't seem to be too far-fetched but it could easily be a Muslim legend.
