[posterboy]

I was suggesting that pit was an extension of it.

I think the j in jt is a remnant of jw (true), jw-?t, (biological father), but only because jw is the only egyptian j- lexeme I know so far, because I like to connect it to IO and Jo- and the jedi knights. For p- I'm not so sure, but something like grand-father or god-father would fit the theme, or less familiar for us distant from the Neolithicum, the stone-father (grey/old, hard/strong, inanimate/false vs true, crafty/fundamental).