Arcana Coelestia #4845
4845. 'Until Shelah my son is grown up' means until the time. This is clear from the meaning of 'growing up' as being of that age, and so as until the time; and from the representation of 'Shelah my son' as idolatry, dealt with above in 4825, 4826, and so as the Jewish religion which, compared with others, was idolatrous, 4825. Consequently the words 'until my son Shelah is grown up' mean until the time that the Jewish religion was able to accept internal things willingly, that is, the spiritual and celestial things of the representative Church, meant by 'Tamar', 4829, 4831, 4843.
Arcana Coelestia #4826
4826. 'And she called his name Shelah' means the essential nature of this. This is clear from the meaning of 'calling the name' as the essential nature, dealt with above where Judah's first two sons, Er and Onan, are dealt with, 4822, 4824. The essential nature of that idolatry is meant by Shelah, for there are many kinds of idolatry. There is external idolatry and there is internal; and in general both involve the worship of falsity and evil.