'Heat and light' in the Word signify love and wisdom. Natural heat and light serve as a clothing and support to spiritual and light, whereby they may be conveyed to a person.

(Referencias: Heaven and Hell 155, 488)

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.