It é rátha tucsat ind...

It é rátha tucsat ind
nem talam ésca grían grind.

(are * they * pledges * they gave * into it /
heaven * earth * moon * sun * sharp)

The pledges that they gave for it were
heaven, earth, moon, and the sharp sun.

This is a half-stanza from the poem "Sóerchlanda Érenn uile", edited by Thurneysen at ZCP 11.57. As Fergus Kelly remarked in EIL (p. 198), "Early Irish legal systems rely heavily on the magical power of an oath. Old Irish sagas make numerous references to the practice of swearing by the elements: anyone who broke such an oath could expect to be punished by the elements themselves." In the tale "Comthoth Lóegairi" in LU, Lóegaire vows to the Leinstermen that he will never again seek tribute from them, taking as his pledges or guarantors "grían 7 éasca, usci 7 aer, lá 7 adaig, muir 7 tír" (sun and moon, water and air, day and night, sea and land). When he later breaks his oath, the elements kill him. The most elaborate such list of guarantors is found in the Metrical Dindshenchas of "Carmun", where it runs to two full stanzas, and is worth quoting for its very length, beginning with "heaven, earth, sun, moon, and sea", and ending with "day and night, shore, heavy tide", with various horses, ears, swords and fruits in between!

Nem, talam, grían, esca, is muir,
toirthe tíre ocus turscuir,
beóil, clúasa, súli, selbtha,
cossa, láma, láech-thengtha.

Eich, claidib, carpait cáine,
gái, scéith is drecha dáine,
drucht, mess, daithen la duile,
lá 's adaig, tráig, trom-thuile.

The expressions "Thug sé grian is éasca air féin" (He vowed by the sun and moon) and "Dar bhrí na gréine is na gealaí" (By the power of the sun and the moon) are still found in Modern Irish.