"The King of Love My Shepherd Is"

A couple weeks ago, I happened to think of the last two lines of "The King of Love My Shepherd Is" - "I nothing lack if I am His / And He is mine forever."  I realized that there's a chiasm:  "I am His / And He is mine."  I don't know if there's any connection here to the cross of crucifixion, but I thought I would at least note it as a rhetorical effect.

When I lookt at the hymn to confirm that I'd remembered those lines correctly, I noticed a small connection between the text and the tune to which it's sung ("St. Columba").  Here's the second phrase:

That triplet corresponds to "He" in the lines "My ransomed soul He leadeth" in the second verse and "But yet in love He sought me" in the third.  This group of three notes in the space that would normally be occupied by one (as in the previous measure) is something of a musical picture of the Trinity.