“In the Indo-Aryan West, 9 was always a most propitious number, for each aspect of a ruling trinity could be multiplied by 3 to create a pantheon of 9. It is not difficult to see that this was the likely origin for our choirs of nine angels, nine heavenly spirits and nine muses. The number also has an innate reference to the nine months in which a child is created within the womb.”
Excerpted from: Rogerson, Barnaby. Rogerson’s Book of Numbers: The Culture of Numbers–from 1,001 Nights to the Seven Wonders of the World. New York: Picador, 2013.