Middle Eastern knife (?)

[motan]

Hi Ian,
It dagger is almost certainly Lebanese. The general type could be either Syrian or Lebanese (not Jordanian), This type of scabbard is common in both (see pic 1). However, this shape of pommel you call thumb rest is common in a certain types of Lebanese daggers (see third from left in pic 2) and the presence of a guard is common in Lebanese daggers, but mostly absent in Syrian ones. The use of solid bone and the way the hilt tapers to a narrow metal part towards the blade is also typical of Lebanon.
This type of dagger is usually seen as a presentation piece and the scabbard is often cast and coated, rather than chiseled and plated. I can not say if that is the case with yours, but it is a special and high quality example of this type (though probably not very old).
Eytan