It's sung to the tune "Wie schön leuchtet." Here's the third musical phrase:
In the third verse, the text here is "A ray of purest pleasure." It's sung to a generally descending phrase, so there's a sense of its "fall[ing]," which is described in the previous line: "At once there falls from God above." (Years ago, I noted that the second half of the line "At once there falls from God above" also descends, matching the "fall[ing]" there.)
Here's the last musical phrase:
In the first verse, the text here, apparently still describing the Morning Star, is "Rule and might o'er all possessing!" Pitch-wise, "Rule" (sung to a D) and "might" (sung to a B) really are over "all" (sung to a G).