What is the meaning of Gatha #140 of the Parayanavagga? Gatha #140 of the Parayanavagga goes as follows:


  “Akincannasambhavam natva, nandi samyojanam iti, 
  evam-etam abhinnaya, tato tattha vipassati: 
  etaṁ nanam tatham tassa, brahmanassa vusimato”
  
  Where can I find some interpretation about this verse ?
I am going to give this a shot.  From my kindergarten level self taught Pali.

key words:


Akincanna: perception of Jhana in No-thingness
nandi: joy, dwelling
samyojanam: bind, fetter
vusimato: insight


when one gains a knowledge that joy or dwelling in content of the infinite consciousness (empty of any permanent nature)-  is a causal of a binding fetter, He practices insight wisdom in that knowledge.  

My opinion, i.e.  Buddha's meditation teachers when he was seeking enlightenment, those two meditation teachers did not see the binding force (fetters) caused by joy in (from) those meditative states so they did not gain any insight.  

further simplify:
when you know that joy in meditation is a binding, you practice insight from that knowledge.