Eternity
In many cases, the use of “eternity” in the Bible is pretty literal, simply meaning forever. This is especially true when the text refers to someone being condemned to hell or elevated to heaven. In some cases, however, “eternity” or “days of old” refers to what the Writings call the Most Ancient Church -- the first church among the earliest people, innocent souls who acted directly out of love of the Lord. Because of this association, things called “eternal” or “everlasting” usually represent the desire for good that arises from love to the Lord. If we love the Lord, then our desire will be to do His will and love as He loves. From that we will have a true desire to love and care for other people. That's the feeling described by “eternal.”
Arcana Coelestia #1849
1849. That 'the nation also which they are going to serve' means the evil who oppress is clear from the meaning of 'nation' and of 'serving'. In the genuine sense 'a nation' means goods, or what amounts to the same, those who are good, for when goods are thus spoken of abstractedly they still have reference to the subject, which is a man, spirit, or angel. In the contrary sense however 'nation' means evils, or what amounts to the same, those who are evil, dealt with in 1159, 1258-1260. 'Serving' however, or slavery, means oppression, as in the previous verse.