7Brady, Conor, and Matthew Seaver. “The Motte.” The Hill of Slane Archaeological Project, 8 June 2015, hillofslane.wordpress.com/the-site/the-motte/.
The geophysical studies undertaken in 2010-11 were inconclusive regarding the potential barrow and other features surrounding the motte. (Brady, Conor, et. al. “Recent geophysical investigations and LiDAR analysis at the Hill of Slane, Co. Meath.” Ríocht na Midhe, Meath Archaeological & Historical Society, XXIV (2013): 134–55.)

The quoted phrase from The Song of Dermot and the Earl, "harrass the enemies," is taken from the text below. The Song of Dermot and the Earl may be read in its entirety here.

Richard the Fleming was his name —
Twenty fiefs he gave him of a truth,
If the geste does not deceive you.
A fortress this man erected
In order to harass his enemies,
Knights and a goodly force he kept there
Archers, Sergeants, likewise.
In order to destroy his enemies;