'Twenty,' when referring to a quantity, signifies everything, or fullness, because it is ten twice. In Genesis 18:31, 'twenty', like all numbers occurring in the Word, signifies things and states. The significance of 'twenty' can be seen in its factors, namely, ten and two.

In the Word, 'Ten,' and 'tenths,' signify remains, i.e. every good and truth which the Lord puts into a person from infancy to the end of life.

'Ten twice,' 'two tenths,' and 'twenty' signify the same thing, but in a higher degree, namely, good. Good things in triplicate signify remains, namely, the good of infancy, the good of ignorance, and the good of intelligence.

(Odkazy: Arcana Coelestia 10222)

10222. 'A shekel is twenty obols' means all the components of good. This is clear from the meaning of 'twenty' likewise as all, and as remnants of good, and also what is holy. For its meaning as all and consequently what is complete, see 9641; remnants of good, 2280; and what is holy, 4759, 7842, 7903. For when 'twenty' has regard to the Lord it means His Proprium, which is Holiness itself, 4176. From all this it is evident why a shekel should consist of twenty gerahs or obols and why it was called the shekel of holiness, as it is in the present verse and elsewhere, such as Leviticus 27:3; Numbers 3:47, 50; 7:13, 19, 25, 31, 37, 43, 49, 55, 61, 67, 73; 18:16. The fact that a shekel was a weight both of silver and of gold, see Genesis 24:22; Exodus 38:24; Ezekiel 4:10; 45:12.