'Three years old,' as in Genesis 15:9, implies all the times and states of the church, which appears from the meaning of 'three' in the Word, a full time of the church from its origin to its end, and as a result, every state of it. So, 'the third day' signifies the end state of the church. 'The third week,' 'the third month,' 'the third year, and 'the third age' signify the same thing. Because the number three signifies the state of the church, it also signifies the state of every individual who is and everything that is a church.

(Notae: Arcana Coelestia 1825)

1825. That 'three years old' embodies all things of the Church as to periods and states is clear from the meaning of 'three' in the Word. Three means the whole time of the Church from start to finish, and so its total state. The final phase of the Church is therefore meant by the third day, by the third week, by the third month, by the third year, or by the third decade, ¹ all having the same meaning. As the state of the Church is meant by the number three, so also is the state of every individual who is a Church, and indeed everything that is part of the Church, as becomes clear from the meaning of that number in the places quoted from the Word in 720, 901.

[2] That 'a three year old heifer' accordingly means the whole time or state of the Church even to its end, that is to say, when it has been vastated, or laid desolate, also becomes clear in Isaiah,

My heart cries out upon Moab, his fugitives flee even to Zoar, a three year old heifer, for at the ascent of Luhith he will go up weeping, for on the road to Horonaim they will raise a cry of ruination. Isaiah 15:5.

Also in Jeremiah,

Gladness and exultation have been plucked from Carmel, and from the land of Moab, and I will make the wine cease from the winepresses. None will tread the hedad; the hedad will not be a hedad. ² From the cry of Heshbon even to Elealeh, as far as Jahaz they uttered their voice, from Zoar even to Horonaim, a three year old heifer, for the waters of Nimrim also will become desolations. Jeremiah 48:33-34.

Nobody could possibly perceive what these details mean unless he knew what is meant by Moab, Zoar, the ascent of Luhith, the shout of Heshbon even to Elealeh, Jahaz, Horonaim, the waters of Nimrim, and a three year old heifer. That a final vastation is meant is plainly evident.

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