Looking in Vendler's book The Poetry of George Herbert--how many years have I had that on my shelf?--I find a few tools that would be worth sharing.
She looks at the poem spatially, tracking the shrinking distance between God and the soul as it goes along. (By the end, I guess, it vanishes altogether, as God is actually ingested.)
She tracks the gradual revelation of the various attributes of Love: first welcoming, then observant, then solicitous, and so on. I like this, too: the poem as sequential and accretive definition.
She tracks as well the hesitations of the speaker: his own self-revelation, or maybe self-transformation. (I'd add to this the way these play out in terms of language--this speaker is constantly adjectival, always describing himself, through the first two stanzas and into the start of the third; then he begins to leave that behind in favor of simple actions, first in the future, and then in the simple past.)
I love her attention to the social comedy of the poem, "like some decorous minuet," as she says (275). She also does good work with how Herbert "reworks his source" (Luke 12:37). He changes crucial details (who comes, who is watching, who changes for the feast) to turn this--
Blessed [are] those servants, whom the lord when he cometh shall find watching: verily I say unto you, that he shall gird himself, and make them to sit down to meat, and will come forth and serve them.to this:
Love bade me welcome, yet my soul drew back,
Guilty of dust and sin.
But quick-ey'd Love, observing me grow slack
From my first entrance in,
Drew nearer to me, sweetly questioning
If I lack'd anything.
"A guest," I answer'd, "worthy to be here";
Love said, "You shall be he."
"I, the unkind, the ungrateful? ah my dear,
I cannot look on thee."
Love took my hand and smiling did reply,
"Who made the eyes but I?"
"Truth, Lord, but I have marr'd them; let my shame
Go where it doth deserve."
"And know you not," says Love, "who bore the blame?"
"My dear, then I will serve."
"You must sit down," says Love, "and taste my meat."
So I did sit and eat.