My eyes fail for your salvation, and for the word of your righteousness.
Read Chapter 119
Augustine of Hippo
122 ...To prefigure His Cross, Moses by the merciful command of God raised aloft on a pole the image of a serpent in the desert, that the likeness of sinful flesh which must be crucified in Christ might be prefigured? By gazing upon this healing Cross, we cast out all the poison of the scandals of the proud: the Cross, which the Psalmist intently looking upon, saith, "My eyes have failed for Thy salvation, and for the words of Thy righteousness" (ver. 123). For God made Christ Himself "to be sin for us, on account of the likeness of sinful flesh, that we may be made the righteousness of God in Him." For His utterance of the righteousness of God he therefore saith that his eyes have failed, from gazing ardently and eagerly, while, remembering human infirmity, he longeth for divine grace in Christ.