Arcana Coelestia #738
738. He is called 'a son of six hundred years' here because, as shown already, 'son' means intellectual truth. He is not however referred to as a son in verse 11 below because there the subject is his temptation as regards things of the will.
Zechariah 12:2
2
Behold, I will make Jerusalem a cup of trembling unto all the people round about, when they shall be in the siege both against Judah and against Jerusalem.