You can read the reference at the bottom of the page here
http://www.northvegr.org/vigfusson/255.php

I do not know what N. G. L. refers to, but it seems to be both a biblical
tradition and a Scandinavian tradition - - possibly of biblical origin - -
since it apparently turns up as a personal name, probably of someone adopted
this way.
Grace
Fred and Grace Hatton
Hawley Pa