Teru tsuki no nagaruru mireba Ama no Kawa izuru minato wa umi ni zo arikeru - Gosen Wakashu(English Translation & Meaning)

照る月の流るる見れば天の川
出づる港は海にぞありける

Roma-ji: Teru tsuki no nagaruru mireba Ama no Kawa izuru minato wa umi ni zo arikeru
English Translation: When I watch the moon
shining as it flows along,
I see that the mouth
of the River of Heaven
opens out into the sea
Meaning: Watching the bright moon flow across the sky, I see that the River of Heaven has its mouth out here in the sea.
Commentary: Book Nineteen Parting Poems 1363

Headnote: "Coming up to the capital after his term in Tosa had ended, on seeing the moon from the boat."
The poet says that watching the shining moon flow along, he finds that the harbor from which the River of Heaven issues lies in the sea. On the voyage home from Tosa, seeing the moon rise from the sea, he concludes that the mouth of the heavenly river the moon sails must be the sea, a view of the moon only the sea could give.
According to the headnote, he composed this on seeing the moon from the boat as he came up to the capital after his term as Governor of Tosa had ended. A poem of the same conceit also appears in the Tosa Diary.
The poet, "Tsurayuki," is Ki no Tsurayuki. A son of Ki no Mochiyuki, he was the chief compiler of the Kokinshu and wrote its Japanese preface. He is also known as the author of the Tosa Diary, and the Ogura Hyakunin Isshu includes his poem "Hito wa isa kokoro mo shirazu furusato wa."

The first line, "Teru tsuki no," means "of the shining moon."
The second line, "nagaruru mireba," means "when I watch it flow," likening the moon's passage to a current.
The third line, "Ama no Kawa," is the River of Heaven, seen as the river the moon sails along.
The fourth line, "izuru minato wa," means "the mouth from which it issues."
The last line, "umi ni zo arikeru," means "lies in the sea, I see," with "zo" closed by the attributive "keru." "Flow" and "harbor" are associated words with "river."
Author: Ki no Tsurayuki
Source: Gosen Wakashu
Prev Poem: Hito goto ni kyō kyō to nomi koiraruru miyako chikaku mo narinikeru kana
Next Poem: Kusamakura momiji mushiro ni kaetaraba kokoro o kudaku mono naramashi ya