In general, things that are “elder” in the Bible represent spiritual states that come before others. For example, of the two sisters Jacob married, Leah was the elder, and represents the affection for true ideas about external life. Rachael, the younger, represents the affection for true ideas about internal life, the life of the mind and spirit. Together they represent the Lord’s advance, while he was growing up as the human Jesus, from the affection for external ideas to the affection for internal ones.

(Reference: Arcana Coelestia 1222, 3819)