An Answer to My Question About Chrism

In my post about the thirty-sixth letter, I noted a passage in which Pseudo-Isidore insists on the annual consecration of chrism.  I was puzzled about the purpose:

None of this has anything to do with Fabian's biography in the Liber Pontificalis, though the same argument does occur in Benedictus Levita. What's going on here? Were there any contemporary ninth-century arguments about the annual consecration of chrism? So many questions.

W.G. reminds me that this is actually highly relevant to the issue of episcopal authority. While ordinary priests needed chrism for a variety of sacramental purposes, only bishops could consecrate it. Pseudo-Isidore wants to keep those priests heading off to the bishop every year for a renewed supply. In other words, he wants his bishops to take advantage of every opportunity to flex their muscles and advertise their authority.