'A seed' signifies the ultimate and primary levels in a person. It also signifies good and truth from the Lord. In an opposite sense, it signifies falsity of doctrine and hellish falsity. 'A seed' signifies everyone who constitutes the Lord's spiritual kingdom and faith grounded in charity.

In Genesis 12:7, 8:15, 16, 'a seed' signifies love and everyone who has love.

(References: Arcana Coelestia 1025)

339. Internal Meaning of Psalm 89

1-2 All Divine truth is from the Lord (13, 10)

3-5 The Divine truth is from Him because there is oneness with the Divine Human (10, 16, 16)

6-9, 13 Thus the Lord has all power (10, 16)

10-14 All of heaven and the church is from Him, (10, 16)

15-18 Happy is he who trusts in the Lord (12, 16)

19-25 The Father to the Lord, or His Divine to His Human that by oneness with Him He has omnipotence over the hells (10, 16)

26-29 N. B. There will be eternal oneness with Him (10, 16)

30-37 Even if those of the church should fail there will be eternal oneness with Him. (10)

38-42 Of the Jewish nation: It has destroyed conjunction with Him, because it has destroyed the church. (4)

43-45 It has utterly repudiated Him. (4)

46-48 Prayer to the Father, that, unless He assist, no one will have eternal life. (13)

49 Unless oneness be effected, (10)

49-51 the hells will otherwise prevail. (10, 8)

52 He assists. (10, 8)