Grey hair
In Genesis 42:38, this signifies the last of the church. (Arcana Coelestia 5550)
In Genesis 44:29, this signifies spiritual good will perish, and so the internal of the church. (Arcana Coelestia 5832)
In Isaiah 46:4, this signifies education even to old age. (Apocalypse Explained 710[3])
