The number nine - 9 - in scripture
Judgment, finality, completion
nine fruit of the Holy Spirit
nine gifts of the Holy Spirit in the Church
18 would be 9x2 thus reemphasising the value of
what nine is about.
citing Bulling here p235 ...
"The number nine is a most remarkable number in many respects.
It is held in great reverence by all who study the occult sciences:
and in mathematical science it possesses properties and powers
which are found in no other number."
[did you know that the quotient of any addition/multiplication of
nine will always add up to nine?
2x9 = 18: 1+8 = 9
2x9 = 27: 2+7 = 9
4x9 = 45; 4+5 = 9
7x9 = 63: 6+3 = 9
and so on; amazing]
"It is the last of the digits, and thus marks the end; and is significant
of the conclusion of a matter."
"The Number Of Finality Or Judgment
for judgment is committed unto Jesus as 'the Son of man.'
It marks the completeness, the end and issue of all things
as to man - the judgment of man and all his works.
[the Son of man] has a factor of 666 which is 9 x 74 "
Now that's an interesting juxtaposition against the beast in
Revelation. For it is the number of a man.
"The Sieges Of Jerusalem
have been 27 in number, or three times nine, and they are
stamped with the number of Divine completeness (3) and
the number of judgment (9)." p236
As we all know the destruction of the first and second temples
in Jerusalem both occurred in the Jewish calendar on the same day
the 9th of Av
The First Temple was also destroyed on the 9th of Av (423 BC)
The Second Holy Temple stood in Jerusalem for 420 years (349 BCE–70AD)
and was torched on the 9th of Av by the Romans.