The prophets frequently refer to the shadow of death, which signifies the profound darkness that comes with death, robbing individuals of all illumination. Just as we say the blind dwell in darkness due to their lack of sight, so too can we not attribute vision to the deceased, who feel and perceive nothing. Thus, poets describe the souls of the departed as shadows, symbolizing dark entities; in Holy Scripture, the connection between the shadow of death and darkness is consistently established. For instance, in Job (Job 3:5): let darkness seize me, along with the shadow of death. Similarly, in Job (Job 10:21-22): before I go to a land of darkness and gloom, a land of perpetual darkness, where light does not exist. Isaiah also proclaims (Isaiah 9:2): The people who walk in darkness have seen a great light; those who inhabit the land and shadow of death, a light has shined upon them. Here, walking in darkness and existing within the shadow of death are considered synonymous.
Since dark regions pose many threats, and traversing them fills us with dread, the Prophet articulates, ‘Even if I walk through the shadow of death, amidst profound darkness where dangers abound, I will fear no evil, for You are with me. Your rod and Your staff, they comfort me.’ This introduces the sixth blessing: the support for the weary or vulnerable individual. The Prophet, having left behind the metaphor of sheep, speaks of people; for weak sheep are not aided by the rod and staff, but rather, shepherds carry them on their backs to safety.
These words could be seen as indicative of paternal discipline, as Augustine suggests; however, they are more accurately interpreted as a source of strength, in agreement with Blessed Theodoret and Euthymius. One might assign the rod to correction and the staff to support. When God observes His chosen ones faltering and not advancing as they should, He employs both means—warnings and words of encouragement—to inspire one and fortify the other. Ultimately, both elements provide solace, as the soul rejoices at the realization that God is invested in its well-being.