Closeness and attachment to God form the very foundation of all existence. Life and light are not independent forces of nature, but rather a constant flow of energy stemming directly from the Divine presence. God acts as an eternal, flowing spring whose waters never cease, completely unlike a gathered pool that is always at risk of drying up [רד״ק, מצודת ציון]. All life is held securely in His hands, and He grants it to those who find favor in His eyes [תורה תמימה, מצודת דוד].
The primary approach among commentators is that this goes far beyond mere physical existence. The natural life of the body acts merely as a channel drawing from this higher source. True vitality is entirely spiritual, rooted in the eternal soul that never faces death [אבן עזרא, מלבי״ם]. Therefore, simply being close to God offers a profound sense of satisfaction, freshness, and genuine living [ביאור שטיינזלץ, מלבי״ם]. This ultimate connection serves as a picture of the World to Come, a state of endless existence entirely free from death or interruption [רד״ק]. Alternatively, being in God's presence can also be understood as a reference to His attribute of strict justice. From this perspective, the eternal life of the World to Come is acquired specifically through the acceptance of suffering [אלשיך].
Just as God is the endless spring of life, He is equally the origin of all illumination. The physical light we experience in our daily lives is nothing more than a single spark of a much greater, divine light. It is only because of this hidden, spiritual illumination that light in our physical world can exist and function at all [מלבי״ם]. The illumination that comes from God is entirely unique and far better than any other light [מצודת דוד]. By clinging to Him, a person is directly granted this profound spiritual brightness and vitality [ביאור שטיינזלץ].
Because light is the most respected and non-physical element in the natural world, it serves as the perfect metaphor for the spiritual reward awaiting in the World to Come—an existence of absolute clarity and complete light, untouched by any darkness [אבן עזרא, רד״ק]. Following the perspective that connects eternal reward to the endurance of hardship, this profound brightness represents the illumination of the Torah. The deepest secrets and underlying truths of the Torah are fully revealed to a person precisely by virtue of the suffering they have accepted and experienced [אלשיך].