To make a long story and religion short, hebrew had a complex number/letter theory. Ever watch Pi?
Well i believe 7 was holy. 11 was infinity, stuff like that. Hope it helps.
Edit: numerology..
http://tinyurl.com/s37ag
uhm.. basically each individual letter had a numerical value or something.
[This message has been edited by Choch (edited 02-27-2006).]