First of all, this is a good time to mention that in my first entry on places ending in -stan, I neglected to include Poland as “Lehistan” (and other pronunciations and spellings in certain other Eurasian Muslim tongues). Naturally in these same languages it is acceptable to refer to the language with “Leh” rather than “Pol” as the root. This practice has survived even in Turkey, where Poland is always referred to as “Polonya” (by contrast, in Iran one makes reference only to “لهستان” and its official language: لهستانی). Turkey’s “Lehçe” contains a “ç” as this suffix does in Central Asia, even though in Turkey it has generally “softened” to a voiced affricate (but in words like this one, the voiceless consonant preceding the consonant allows it to maintain its voiceless character).
The reason this is of interest is because in Turkey there is, by coincidence, a word “lehçe” meaning “dialect”. This is derived from the Arabic “لهجة” (lahja), but the proximity of “j” to the voiceless “h” causes a similar devoicing as with the suffix in “Lehçe”, except in this half of the merger the “ç” is innovation (Arabs lack an independent native “ch” phoneme).
This “Leh” is derived from the name “Lech”, which is a Polish name, and an important one indeed. The whole concept is a bit like referring to Hungary as “Atillaland”, which would be kind of cool, actually.
At any rate, that, Lydia, is the source of the confusion.