Notes on Book of Psalms (Author Bishop Richard Challoner (ed.))
78:69 As of unicorns: That is, firm and strong like the horn of the unicorn. This is one of the chiefest of the propositions of this psalm, foreshewing the firm establishment of the one, true, and everlasting sanctuary of God, in his church.
Original Douay-Rheims from Project Gutenberg - Massive cleanup of OCR problems and editing done locally.