Y
ou reach me out of the age of the air clear
falling toward me
each one new
if any of you has a name
it is unknown
but waited for you here
that long
for you to fall through it knowing nothing
hem of the garment
do not wait
until I can love all that I am to know
for maybe that will never be
touch me this time
let me love what I cannot know
as the man born blind may love color
until all that he loves
fills him with color
--W.S Merwin
Generally when Merwin writes a poem "to" something or someone, the "I" in the poem is talking "to" that "person." So he is addressing the rain (and, the raindrops.) That seems clear enough in the first stanza. But there are some tricky tenses and referents in the second. Perhaps what waited was the unknown name:"rain." Something perhaps is suggested about individuality and what they are in common, as well as the difference between the physical drops and their name. The "it" could be the rain again, but it more likely seems to be the air the rain falls through.
In the next stanza, "hem of the garment" is addressed, often interpreted as a Biblical reference, an instrument of revelation perhaps, but it may still be (at the same time) the rain. The imploring "touch me this time" would still be the rain but as a kind of revelation? In any case, the final lines are very powerful. The repetition of word sounds in the otherwise awkward "maybe that will never be" sets up this powerful repetition of "color," partly through the music of the lines. Another repetition in sound and sense is the word "know" (or "knowing") that appears three times in this short poem, each time in some way incomplete. What lies beyond it can only be expressed in the final lines and what they suggest to us.