(a) It occured to me on Tosafos "Hamispalel" to ask why Tosafos speaks
of R. Yitzchak waiting for someone else, using the phrase "Meayen basefer".
What is the difference between "lomed Torah" and meayen basefer?
(b) Also, regarding Abaye's discussion of the Mazikin. I have heard it said
that the Rambam did not believe in Shedim (I think the Gra mentions this in
Shulchan Aruch). How would Rambam have understood this gemara?! Not to
mention seeing them with the powdered cat's placenta!
(c) Finally, what does the gemara mean to say when it quotes amoraim who know
what is written in Hash-m's tefillin? If this is a drash of some kind, is
this telling us that the drash is the source of Hash-m's parshios? And of
course, what does it mean (even according to PSHAT!) to say that Hash-m
wears tefillin? Is it possible to say that this discussion is telling us
MORE about the deeper significance of OUR own tefillin (and our being bound
to Hash-m) through a mashal about Hash-m and his tefillin?
1) Good "Diyuk." "Me'ayen ba'Sefer" means that he was not learning with a sense of being situated there for a long time and for intense learning; rather, since he was ready to get up and leave as soon as he could, he was only "Me'ayen ba'Sefer."
2) The Vilna Ga'on (Yoreh Deah 179) argues with the Rambam. Indeed, our Gemara seems to clearly contradict the Rambam. "Tzarich Iyun" to find a resolution for the Rambam.
(a) Yes, the Derashah is the source for our knowledge of what is written in Hash-m's Tefilin.
(b) Yes, excellent point -- this discussion of the Gemara seems to be telling us more about the deeper significance of our own Tefilin, as well as the nature of Hash-m's relationship with us, which is represented by His Tefilin and what is written inside of them, and by our Tefilin and what is written inside.
One could also point to this powerful midrash and its implications for the kofrim who reject mitzvos like tefillin, including the Karaites. Also, if you do come across a terutz for Rambam about this gemara and the shedim, I would like to know about it! Thanks.