In Heretics of Dune, FH wrote: Waff closed his eyes and waited for the others to leave. Masheikh! How good it was to name themselves in kehl, speaking the language of Islamiyat, which no Tleilaxu spoke outside his own secret councils; not even to Face Dancers did they speak it. Nowhere in the Wekht of Jandola, not to the farthest reaches of the Tleilaxu Yaghist, was there a living powindah who knew this secret.
Yaghist, Waff thought, rising from his bench. Yaghist, the land of the unruled.
In Chapterhouse: Dune, FH wrote: "The Wekht of Jandola is no more," he said. "Billions of us slain by those whores. To the farthest reaches of the Yaghist, we are destroyed and only I remain."
Yaghist, she thought. Land of the unruled. It was a revealing word in Islamiyat, the Bene Tleilax language.
FH appears to have been using it as synonymous with Yaghist, the realm of the Tleilaxu. (The variant passage in the other thread pretty much equates it to "Tleilaxu hegemony".)
Jandola is an actual place in Pakistan, but there's nothing online (other than Dune references) that associate it with something called a "wekht". (It doesn't appear to be a famous archeological site or architectural object, for example.) I've wondered what "wekht" derives from, but have never been able to find anything. The word isn't in the Graham and Doughty books, either.
What's brought this up all of a sudden is a couple of google hits on HToD that I noticed in the access logs. Seems a guy named Rick Wakely (ring any bells for anyone?) has been tooling around the Web looking for the origins of wekht, kehl, Yaghist, and a couple other Tleilaxu terms. (Not with much luck, it appears.)
I guess I need to check the lists of FH's books to see if there were any old travelogues for Persia, Afghanistan and India.