For more information on the negative particle לְבִלְתִּי see Gesenius §114s. Also, see BDB pg. 116b.
In this video we begin to look at the Biblical Aramaic portions of the OT. We begin with the smallest portion: Jeremiah 10:11.
Brown-Driver-Briggs has a helpful article on יֵשׁ on page 441.
Also see GKC§102a,b or Fuller chapter 9.
For a very helpful explanation on the use of the מן preposition, see BDB.
Other examples of the vav+perfect showing purpose include Gen. 35:5; 1 Sam 25:21; 1 Kings 2:31; 13:3.