Here are some excerpts from Swedenborg's "Arcana Coelestia" that help explain the inner meaning of this chapter:

AC 1279. The subject treated of is the first Ancient Church, which was after the flood (verses 1 to 9).

AC 1280. Concerning its first state, that all had one doctrine (verse 1); its second state, that it began to decline (verse 2); its third, that the falsities of cupidities began to reign (verse 3); its fourth, that men began to exercise dominion by means of Divine worship (verse 4) and therefore the state of the church was changed (verses 5 and 6); so that none had the good of faith (verses 7 to 9).

AC 1281. The second Ancient Church is then treated of which was named from Eber--and its derivation and state, which finally ended in idolatry (verses 10 to 26).

AC 1282. The origin of a third Ancient Church is treated of, which from being idolatrous became representative (verses 27 to 32).

1459. Verse 10 And there was a famine in the land; and Abram went down into Egypt to sojourn there, for the famine in the land was serious.

'There was a famine in the land' means a lack of cognitions which still existed with the Lord when He was a boy. 'And Abram went down into Egypt to sojourn' means instruction in cognitions from the Word, 'Egypt' meaning knowledge comprised of cognitions, 'sojourning' receiving instruction. 'For the famine in the land was serious' means a great lack in His External Man.