In a general sense, mourning in the Bible represents a state of grief over the lack of desires for good and true ideas about life. This often happens when a church or an aspect of a church has fallen away from the Lord and has been devastated. It can also be when a new church or state of a church is soon to begin, and there is nothing yet in place. In particular, especially when paired with "weeping," "mourning" has do with the loss of all desire for good and the presence of evil; "weeping" in those cases has to do with the devastation of thought and knowledge.

In general, trees represent the deepest and most significant intellectual concepts: the ones that come to us most directly from the Lord. This varies depending on us and our states: the people of the Most Ancient Church, who were in a state of loving the Lord, understood truth automatically and internally through what the Writings call "perception"; people in lower states (including most of us) have to work a little harder to learn it from the Word and by willing to follow the Lord. In other parts of the Bible, especially in the prophets and New Testament parables, the meaning of "tree" is broader, meaning not just a person's intellectual concepts but the whole person.

'Trees,' as in Joel 1:10-12, signify knowledges.