Arcana Coelestia #2633
2633. 'A son eight days old' means a beginning and continuation. This is clear from the meaning of 'the eighth day'- the day on which male infants were circumcised - as any beginning whatever and so the continuation of that new beginning, dealt with in 2044.
Arcana Coelestia #2044
2044. That 'a son eight days old' means any beginning whatever to purification is clear from the meaning of 'the eighth day'. 'A week', which consists of seven days, means the entire period of any state and length of time - of reformation, regeneration, or temptation, either of the individual in particular or of the Church in general. So the expression 'week' is used whether the period is one of a thousand years, or of a hundred, or of ten, or else one of days, hours, or minutes, and so on, as may become clear from the places quoted in Volume One, in 728. And because the eighth day is the first day of the following week it here means any new beginning whatever. From this it is also clear that just as circumcision itself was a representative of purification, so also was the time when it took place, namely the eighth day. Not that the uncircumcised on that day entered a purer state and on that account were made pure. Rather even as 'circumcision' was a sign meaning purification, so 'the eighth day' meant that such purification ought to go on all the time and so always to be taking place as if from a new beginning.