Written on the day of the festival when Captain Michinobu had been a dancer there and we had been there together, after we had both been promoted to the Fourth Rank.
いにしへの山井の水に影みえてなをそのかみの袂こひしも
| inisiFe no yamawi no midu ni kage miete nawo sono kami no tamoto koFisi mo |
In the ancient Indigo waters of a mountain spring Do I see your face; Still are those long gone, god-touched, Sleeves dear to me. |
Based on your translation, it appears that there may be a pun in this poem on the similarity between 山井•やまゐ (mountain well) and 山藍•やまあい/やまい (mountain indigo plant). I seem to recall from reading elsewhere that indigo robes were part of the dancers’ attire; is that accurate?
http://www.wakapoetry.net/yamaai/
That the robes may have been indigo does ring a bell with me, too, but I can’t be definite without making some more checks.
I found a mention of it in the endnotes for section 84 in Meredith McKinney’s translation of The Pillow Book. “These young men, who officiated in the religious ceremonies, wore Lesser Abstinence (ritual purificatory abstinence for Shinto festivals, etc.) robes, white with a design in mountain indigo dye.” (Section 84, note 5, p. 320.)