Corpus of Electronic Texts Edition
Cath Maige Tuired: The Second Battle of Mag Tuired (Author: [unknown])

section 72

Then Ogma threw the flagstone, which required fourscore yoke of oxen to move it, through the side of the hall so that it lay outside against Tara. That was to challenge Lug, who tossed the stone back so that it lay in the centre of the royal hall; and he threw the piece which it had carried away back into the side of the royal hall so that it was whole again.