By the twilight in the morning, as I roved out upon the dew.
With my morning cloak around me intending for my flock to view.
I there espied a fair one, I own she was a beauty bright,
And I took her for Diana, the evening star that rules the night.

I being so much surprised by her it being the forenoon of the day,
To see this lovely fair one coming o'er the banks of sweet Lough Neagh.
Her snow-white breast lay naked and her cheeks they were a rosy red,
And my eyes were captivated by the two black eyes rolling in her head.

‘Fair maiden’, I cried, ‘your love I crave, for beauty is the lord of all.
I will wrap you in my morning cloak and I'll bring you back to Easter Snow.’
‘Go home, consult your parents, and indeed kind sir, I'll do the same.
And if both our parents they give consent, neither you nor I can share [bear] the blame.’

“Paddy Tunney’s mother Brigid appears to have been the oral the source of this in Ireland; another version was recorded in New Brunswick, Canada. Sam Henry included a 1925 version in his ‘Songs of the People’ column in the ‘Northern Constitution’ newspaper under the title Westersnow and an earlier one was discovered in J.P. McCall’s unpublished songbook, where it was said to have come from ‘County Carlow/County Wicklow’, there given the title Esther Snow. Collector Sean O’Boyle wrote of it:

‘Estersnowe is the name of a townland in Roscommon. Originally the place was known by its Gaelic name Diseart Nuadhan (St. Nuadha's Hermitage) but in the process of adaptation to the English language in Elizabethan times, it became known as Issertnowne. By the nineteenth century the people, when speaking English, called it Estersnowe and rationalised that strange name into Easter Snow. In County Antrim where there is a strong Scots influence, the song is known as Wester Snow.

An instrumental version of the tune is in the Standford-Petrie Collection with two titles in Irish- Sneachta Casga (a literal translation of Easter Snow) and Diseart Nuadhan (the original Gaelic name of the district). The final folk etymology of the name was one I heard from the Donegal Fiddler John Doherty, who played the tune for me but did not know the words of the song. He called the tune Esther Snow and told me that Esther was "a most beautiful lady, with skin as white as the snow." And then with equal authority, he added: “She was six foot one.” The prosody of the song is particularly interesting, being an echo of the Ochtfhoclach form with double assonantal rhymes (Aicill Dubalta). The double rhymes occur in this song only at the line endings:

At twilight in the morning as I roved out upon the dew,
With my morning cloak around me, intending all my flocks to view.
I spied a lovely fair one, she was a charming beauty bright,
And I took her for Diana or the evening star that rules the night.’”

Reference:
The Irish Song Tradition, Seán O Boyle, 1976.
Jim Carroll