As I've heard it, it involves opening a Tanach to a random verse; I heard something it specifically being some Amsterdam printing of the Tanach (anyone back me up here?).  There are some famous stories about its use, though these may be no more than hearsay:


One rabbi who got the verse, "do not use witchcraft or divinations!"
When Rabbi Joseph Breuer was ill and needed an additional name, they found the verse "Shimon and Levi are brothers"; his "brother" in leading the KAJ community was Rabbi Shimon Schwab, so he became Levi Joseph Breuer.
I think there's one with R' Aharon Kotlar, debating coming to America in 1941, and finding (Exodus 4:27) "Hashem told Aharon, go greet Moshe in the desert", referring to Rabbi Moshe Feinstein (who had made it to America in 1936). H/t Alex (see comments below).


As far as how/when/why to use it, eh good question.

What is the Gorel Hagra?
just want to ask if there are any other suggested alternatives for cloning a node for drupal 7. Now I know most of you will answer "Node Clone Module", but is there any other module out there that can do the same thing? Thanks.
