"it developed" It developed from 'point' via 'corner' and 'angle' to 'place'. But how and why we'll never know. How does the point of a weapon turn into place.

Well, I condensed my rather quick skimming of the long entry in Grimm's dictionary. It's online and you can follow the development here (link).

[Addendum: another odd development. In Old Icelandic, oddi meant both 'point' and 'three' or 'odd'. My Dutch etymological dictionary shows the same situation holds in Dutch: "oord ... "punt, kant, rand, spits van een wapen, hoek, vierde deel ... stuk land, tijdstip, begin".]

Ceci n'est pas un seing.