A profound milestone is reached with this declaration of eternal thanks and faith, marking not just the end of a single prayer, but the solemn conclusion of the first of the five books of Psalms. The primary approach among commentators is that this outpouring of gratitude reflects a traditional scribal custom to thank God upon completing a manuscript. The author expresses deep appreciation to God for the help in finishing the book [רד״ק, מאירי, ביאור שטיינזלץ], and for providing His holy spirit to inspire the composition of these prayers [מצודת דוד]. In this light, the call to bless God serves as a declaration of praise [מצודת ציון], reminding us of the constant duty to offer thanks at all times [אבן עזרא]. Alternatively, some connect this gratitude directly to the immediate context of the prayer, viewing it as a personal promise. The author vows that once he recovers from his illness and is fully healed, he will offer this profound blessing to God [רש״י].
The boundless nature of this praise is understood from several different angles. Most commentators view it on a timeline, meaning the praise extends from the very beginning of time until the very end, lasting forever [רד״ק, ביאור שטיינזלץ]. A more specific view suggests this timeline represents our personal journey: we bless God throughout our lives in this world, continuing until we reach the World to Come, where our gratitude to Him will finally be perfect and complete [מאירי]. Breaking away from the concept of time, another perspective understands this boundlessness in terms of physical space, meaning God's praise stretches from one end of the earth to the other [מצודת דוד]. A different approach links this eternal nature to the people of Israel. The bond between God and Israel existed before the creation of the world and will endure forever, guaranteeing that God will always provide a path of return and repentance for His people until their ultimate redemption [אלשיך].
The prayer ends with a doubled word of affirmation, serving as a firm seal of truth [אבן עזרא]. It functions as a declaration of fulfillment, much like a person answering in agreement after hearing a blessing to confirm its reality [רד״ק, מצודת דוד]. Repeating the affirmation strongly emphasizes the absolute certainty that the blessing will be fulfilled [מצודת ציון, רד״ק, אבן עזרא]. Ultimately, this repetition also cements a deep faith in the future, looking forward to the time when God's kingdom will be fully and perfectly revealed [אלשיך].