A profound declaration of eternal loyalty binds the memory of a ruined city to the very physical and spiritual survival of those in exile. Remembering is not merely a mental exercise; it is a basic requirement for a person's ability to function.
The primary approach among commentators is that this oath represents the voices of the exiles, with each poet making the vow quietly in their own heart [אבן עזרא, מצודת דוד]. Another perspective suggests it is the collective voice of the entire nation of Israel [רש"י]. A unique view frames the words as the Holy Spirit speaking directly to Jerusalem to offer comfort. When the people weep over Zion, Jerusalem fears she has been left behind. In response, the Holy Spirit reassures the city: Is it possible that God's attribute of kindness, referred to as the right hand, could ever forget you? [אלשיך]. This idea that God never forgets Jerusalem aligns with a tradition stating that since the destruction of the Temple, perfect joy has ceased even for God Himself [תורה תמימה].
The vow not to forget stands in direct contrast to the earlier moments of weeping, which were driven by the active memory of Zion [אבן עזרא]. Jerusalem is portrayed as the absolute center of life and action. Forgetting the city is deemed as impossible as a person forgetting to use their own right hand [מלבי"ם].
If the oath is broken, a severe consequence falls upon that right hand. Rooted in the context of exiled musicians refusing to perform for their captors, one interpretation is that the hand will completely forget how to play music and pluck the strings of a harp [רד"ק, אבן עזרא, מאירי]. A broader understanding suggests that the right hand—a person's strongest and most essential tool—will lose its strength, its movement, and its ability to perform any work whatsoever [ביאור שטיינזלץ, מצודת דוד, מאירי]. Some explain that the hand will simply wither away [אבן עזרא].
This vow establishes a lasting principle: even in times of great success, the memory of the destruction must be elevated above all joy. Every moment of celebration must carry a trace of sadness because of this memory [מלבי"ם]. This concept translates into daily life and practice. For example, Jewish law dictates that a woman putting on jewelry should leave a small area near her temple bare, serving as a constant, physical reminder of Jerusalem [תורה תמימה].