תהלים, פרק פ״ט, פסוק ל״ו

A profound, unbreakable guarantee lies at the heart of the divine relationship with the Davidic dynasty. God binds Himself with an absolute oath, ensuring that the royal line will endure forever. Even in moments when the kingship appears suspended or completely hidden from view, its ultimate survival is certain.

The primary approach among commentators is that the singular nature of this oath reflects its absolute finality—a commitment sworn once and for all, never to be altered [רד״ק, מצודת דוד, ביאור שטיינזלץ]. Others view this uniqueness differently, suggesting it marks the only instance God swore by His holiness, or that this single oath is simply powerful enough on its own [אבן עזרא]. It can also be understood as a comprehensive promise that wraps all previous conditions into a single declaration [אלשיך]. Taking a distinct approach, one perspective notes that human oaths normally involve two parts—a condition and the oath itself. Here, however, the promise is entirely unconditional, making it a single, unified commitment [מלבי״ם].

To seal this promise, God swears by His own holiness or His very name [רד״ק, אבן עזרא, ביאור שטיינזלץ]. Alternatively, this solemn vow may refer to the heavens themselves, which endure forever and act as an eternal witness to the agreement [אבן עזרא].

The phrasing of the declaration mirrors standard human expressions of swearing [רד״ק]. It reads as an incomplete thought, formulated the way people speak, implying a severe consequence upon the speaker if the promise to David were ever broken. This human style of speech is used to convey an absolute, undeniable refusal to go back on the word given [מצודת דוד]. The divine commitment not to deceive is generally understood as a firm rejection of falsehood [מצודת ציון, ביאור שטיינזלץ]. However, the nature of this unbroken promise is also compared to a natural spring. Just as a reliable spring never dries up or stops flowing, this divine guarantee will never fail or cease [רש״י].

The essence of this unbreakable word is that David's descendants and his throne will never be lost. There may be periods when the people lack merit, causing the kingship to be temporarily suspended and hidden. Yet, just like the moon that shrinks and vanishes at the end of the month only to reappear, the royal line is guaranteed to endure. It is destined to return and shine with full strength in the days of the Messiah [אבן עזרא, מלבי״ם].