77. For to 'dig up the earth with the hoof' is to subdue the flesh by strict abstinence. And the more the flesh is pressed down, the more securely does the soul rejoice in heavenly hope. Whence to the earth dug up is fitly annexed: 'He exults boldly.' For because he powerfully represses what assails him, he boldly exults over those things which he desires in the eternal peace; and the mind is the better composed for seeking the things above, the more strictly the body is subdued from unlawful things. Whence rightly it is said through Solomon: 'Diligently till thy field, that afterward thou mayest build thy house' (Prov. 24:27).
For he well builds the house of his mind, who first purges the field of his body from the thorns of vices, lest, if the briars of desires should thrive in the field of the flesh, within, the whole fabric of the virtues be destroyed by the hunger of good work as it grows. But everyone set in the very contest of war discerns the fraud of the enemy the more subtly, the more strictly he presses down his own body as a kind of helper of the enemies. Whence also, after the crushing of the body, after the gladness of the heart, rightly is subjoined: