155, 299 What is "the third heaven"

From the third heaven, where God resides

155 Northfield

299 New Jerusalem

The only biblical reference I'm finding is from Paul, speaking third person about himself (a not uncommon literary device.)
2 Corinthians 12:4 (KJV)
I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth;) such an one caught up to the third heaven. And I knew such a man, (whether in the body, or out of the body, I cannot tell: God knoweth;) How that he was caught up into paradise, and heard unspeakable words, which it is not lawful for a man to utter.

I suspect that somewhere out there one might find some esoteric cosmology connected with this, but in my limited library I'm just seeing the pretty plain sense of the words. And I think this is what would have been evident and important to the hymn writer also.

One standard commentary (Barclay) says of the third heaven "He simply means that his spirit rose to an unsurpassable ecstasy in its nearness to God."

My study bible notes that according to vs. 4, the "third heaven" is where paradise is located. (It goes on to note that heavenly journeys were a popular means of claiming divine authentication and were apparently used by Paul's opponents for this purpose.)

All of this suggests that the hymn writer got it right:
From the third heaven where God resides, that holy happy place
The new Jerusalem comes down adorned with shining grace.

The "new Jerusalem" coming down takes us back to Revelation 21:2 (KJV)
And I John saw the holy city, new Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband.


Thank you Mary Mac for this question (and I'm not forgetting your second question about nature imagery)