It isn't!
But you do find SUNKLHTOS and EPIKLHTOS a few times.
The verb it comes from, PARAKALEW, is used 138 times. It is used 24
times in Isaiah, and sometimes the places it occurs have no parallel in the
Hebrew text.
A famous passage is Isa 40:1
PARAKALEITE, PARAKALEITE TON LAON MOU LEGEI hO QEOS
Hope this helps!
David McKay
music@fl.net.au