... et miserere, quia peccavimus tibi."
"Hear our entreaties, Lord, and show Thy mercy;
for we are sinners before Thee."
[I'm quite shamelessly borrowing this from Whispers in the Loggia. Click on the link there and listen to the melody. It's a beautiful chant! Some great musical recommendations there too. Allegri's Miserere is simply divine.]