Augustine of Hippo
The reason for humanity's downfall is that the first man did not experience the absence of hell; rather, it was the influence of arrogance that led him there, with the wicked hand of the sinner—specifically, the arrogant hand of the adversary—pushing him forward. The tempter declared, "I will set my throne to the north," and similarly coaxed him, "Taste, and you shall be as gods." Indeed, our pride is the source of our fall, drawing us into the shadow of death. Yet, while pride inflicts wounds upon us, humility serves as our remedy. God, embodying humility, comes to heal humanity from all the injuries caused by arrogance. Therefore, when he refers to the foot, it signifies man's passions that arise from having turned away from God and experienced a fall.
Where have they stumbled? In their arrogance, they have been brought down and cannot rise again (cf. Psalm 35:13). Yet, if pride has caused them to fall so deeply that they cannot regain their footing, it is humility that will allow those who possess it to stand firm eternally. Thus, the one who proclaimed, The broken bones shall rejoice, first expressed, Let me hear joy and gladness (Psalm 51:8).
But why do you harbor such fear regarding this matter? It is written, "All they that do iniquity have fallen" (Psalm 35:12), indicating that they have descended into that great abyss, which is described as Your judgments being like a vast chasm, revealing that they have reached the depths where scorned sinners lie. What initiated their downfall? It was the folly of pride. Consider the foundation of pride. When they came to know God, they did not honor Him as God. Pride rose against them, and they plunged into the depths. The Lord allowed them to pursue their hearts’ desires, leading them to actions that were unpleasing (Rom. 1:21-24). The essence of sin and its pinnacle trembled before the One who warns, "Let not the foot of pride come against me." Why this mention of "the foot"?
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It signifies that through their proud walk, humanity turned away from God. The foot symbolizes one’s affections. "Let not the foot of pride come upon me; let not the hand of the wicked cast me away," meaning let not the deeds of the wicked entice me to imitate them. Why address pride in this context? It is through pride that all who commit iniquity have stumbled. Thus, when the Lord sought to caution His Church, He proclaimed, "She shall watch over your head, and you shall watch over his heel" (Gen. 3:15). The serpent is vigilant when the foot of pride targets you, waiting for a moment to bring you down. But remain alert to his head: the root of all sin is pride (Sirach 10:13). From this source, all who act wickedly have fallen; they are cast out and unable to stand. First, he who in Truth did not endure; then through him, those whom God expelled from Paradise. In contrast, the humble one—who professed himself unworthy to loose the strap of his sandal—remains anchored, attentive to the voice of the Bridegroom, filled with joy; not due to his own merit, lest the foot of pride rise against him, causing him to be cast out and left unable to stand.