... of a [text] widget.

----

From some discussion on comp.lang.tcl:

 Neil Madden wrote:
 > 
 > .t index insert
 > 
 > thus:
 > .t insert [.t index insert] "Some text\n"
 > 

 It's even better than that, Neil.  The word "insert" is a special mark
 in the tag widget, so you can use it just like "end."  (See "Marks" and
 "The Insertion Cursor" on the text man page.)  So you can do this with
 just one call to the text widget:

  .t insert "insert" "Some Text\n"

 Bob