Yo to tomo ni kokoro no uchi ni sumu tsuki o ari to shiru koso haruru narikere - Kinyo Wakashu(English Translation & Meaning)

世とともに心のうちにすむ月を
ありと知るこそ晴るるなりけれ

Roma-ji: Yo to tomo ni kokoro no uchi ni sumu tsuki o ari to shiru koso haruru narikere
English Translation: Ever with the world
within the heart there dwells clear
a moon, and to know
that it is there, it is this
that clears away the clouds
Meaning: To know that there is a moon dwelling clear within one's heart through all one's days, that indeed is what it means for the clouds to clear.
Commentary: Book Ten Miscellaneous Poems II 642

To know that there is a moon dwelling clear and bright in one's heart, unchanged through all time, is itself the clearing of the heart's delusion. Likening the Buddha nature inherent in each human heart to the moon, the poem teaches that awakening to it is enlightenment.
The moon poems that run from 628 in this book here turn to the moon within the heart. Like 634 and 640 in this book, which sing of noticing the jewel in the lining of one's robe, this poem sings of recognizing what lies within oneself.

First line, 'yo to tomo ni', means at all times, unchanging.
Second line, 'kokoro no uchi ni', means within the heart.
Third line, 'sumu tsuki o', means the moon that dwells and shines clear, joining sumu, to dwell, with sumu, to be clear. The moon within the heart stands for the Buddha nature inherent in everyone.
Fourth line, 'ari to shiru koso', means to know that it is there, the particle koso reaching to the final line.
Final line, 'haruru narikere', means is the clearing, the copula nari followed by kere, the realis of the exclamatory keri, answering koso. Moon, clear and clearing are associated words.
Source: Kinyo Wakashu
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