Irinuru ka akanu wakare no kanashisa o omoishire to ya yama no ha no tsuki - Senzai Wakashu(English Translation & Meaning)

入りぬるか飽かぬ別れの悲しさを
思ひ知れとや山の端の月

Roma-ji: Irinuru ka akanu wakare no kanashisa o omoishire to ya yama no ha no tsuki
English Translation: Have you set at last?
is it to make me know the grief
of a parting not yet sated
that you sink, O moon
upon the mountain's rim?
Meaning: Have you sunk out of sight already? Moon on the mountain's rim, do you mean to make me understand the sorrow of a parting I can never have enough of?
Commentary: Book Nine Poems of Lament 594

Headnote: "Composed watching the moon until it set, after the later Lay Prince-Abbot passed away"
Composed after the death of the later Lay Prince-Abbot of Ninnaji, Prince Kakushō, as the poet watched the moon until it was about to set. Have you set already, he asks; do you mean to make me know the sorrow of a parting I cannot have enough of, moon on the mountain's rim? He overlays the moon sinking behind the mountain with the passing of the prince-abbot from this world, and through parting from a moon he never tires of watching, he is made to feel anew the sorrow of parting from the prince. Prince Kakushō died in 1169.
The author, "Bishop Inshō," seems to have been a monk of Ninnaji in the late Heian period, but little is known of his life.
Poem 588 of this book is by Prince Kakushō himself, remembering his mother Taikenmon'in, and this poem in turn mourns that same prince.

First line, "irinuru ka": "nuru" is the attributive of the perfective "nu," and "ka" a question tinged with exclamation, "have you set already?" The moon's setting behind the mountain is overlaid with the prince's death. The poem pauses here.
Second line, "akanu wakare no": "aka" is the irrealis of "aku," "to be sated," and "nu" the attributive of the negative "zu," "a parting one can never have enough of."
Third line, "kanashisa o": "the sorrow" of parting from the prince-abbot.
Fourth line, "omoishire to ya": the interrogative "ya," with words such as "irinuru" left unsaid after it, "do you mean me to understand?"
Fifth line, "yama no ha no tsuki": ending on a noun, it names last what is being addressed. Poems 560, 576 and 603 of this book also sing of the moon gazed at in remembrance of the dead, and 600 sings of clouds trailing "yama no ha ni."
Author: Inshō
Source: Senzai Wakashu
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