5 “To perfect My steps in Your paths”. That the love of the Church might be perfected in the strait ways, whereby she arrives at Your rest. “That My footsteps be not moved.” That the signs of My way, which, like footsteps, have been imprinted on the Sacraments and Apostolical writings, be not moved, that they may mark them who would follow Me. Or at least, that I may still abide fixedly in eternity, after that I have accomplished the hard ways, and have finished My steps in the straits of Your paths.
Source: The Enarrations, or Expositions, on the Psalms (New Advent)