Okay, here goes. This is the text as it appears in Rois Ni Ogain's collection "Duanaire Gaedhilge", Vol I, published in the 1920s. The spelling of the Irish is a trifle old-timey.

Deirin de, deirin de!
Ta an gabhar donn ag labhairt 'san bhfraoch!
Deirin de, deirin de!
Taid na lachain ag screadaidh 'san bhfeith.

[The words "deirin de" repeat as above in each verse.]

Gheobhaidh ba siar le heirghe an lae,
As raghaidh mo leanbh d'a bhfeighilt ar fear.

Eireochaidh gealach as raghaidh grian fe
Is tusa mo leanbh as mo chuid de'n tsaoghal

Ta nead smolaighe im choifrin fein
Ta, agus or dom stoirin fein.

Leigfead mo leanbh ag piocadh smear
Ach chodladh go samh go fainne an lae.

TRANSLATION (My own, therefore rough!)

Deirin de, deirin de [According to O Donaill's Irish Dictionary, these are nonsense words used in a child's game played by twirling a glowing stick.]

The brown goat is bleating in the heather
The ducks are calling in the swamp.

Cattle will go westwards at daybreak
And my child will go to mind them as they graze.

The moon will rise and the sun will set
And you are my child and my life's portion.

There is a thrush's nest in my little coffer
Along with gold for my own darling.

I will let my child pick blackberries
and sleep soundly until the break of day.

Thanks for reminding me of this charming text!