Cannot delete "Blessed touch" spell from spellbook
The NPC Ygfa sells a spell called "Blessed touch".
It looks like the same spell effect attached to the Ritual birthsign.
In Vanilla Morrowind, if you visit Ygfa and buy the spell, you can still remove it from your spellbook later.
In OpenMW 0.40 "You can't delete this item from the magic menu".
(RM-3627 from redmine: created on 2016-11-20 by Hla Mas, , closed on 2016-11-20 by R. D.)