“Not without purpose did [Christ] choose this class of death, that He might be a teacher of that breadth, and height, and length, and depth," of which the Apostle speaks (Ephesians 3:18)...
Length is the tree's extent from the beam to the ground; and there it is planted—that is, it stands and abides—which is the note of longanimity …" - St. Thomas Aquinas,
Summa Question 46