Kh instead of S in Yajur Veda

[Georg von Simson]

On March 5 Madhav Deshpande wrote:
>Just to be more specific, the change of .s to kh takes place in the
>Maadhyandina tradition of the Zukla-Yajurveda, where the passage i.se tvaa
>is recited as ikhe tvaa.

A change from .s to kh looks rather dramatic if we take kh as an
aspirated occlusive. But is it not probable that the letter kh was
used to write either a palatal or a velar fricative (spirant) (like
in German ich or ach), a sound that would be near to the
correspondant sibilant (which is also a spirant)? The transition to
the aspirated occlusive might be a rather late phenomenon, supported
by the script. Of course, this would presuppose that writing plays a
part somewhere in the process ...

>The Maadhyandinas are found mostly in north
>India, their southernmost expansion reaching the region of northern
>Maharashtra.  I think there is a likely regional/dialectal connection of
>this pronunciation with northeastern regions, where in Prakrits/Pali one
>often finds kh for Sanskrit .s, for instance lakkha.na for
>lak.sa.na/lak.sma.na.

But this is in so far different as the sibilant here is assimilated
to a precedent occlusive.

Best wishes,
G.v.Simson