An eternal divine promise establishes a leader's unshakeable status, blending rule, justice, and the dedicated service of God. God makes an absolute oath from which He will never retreat. His spoken word serves as an unbreakable vow, ensuring He will not reverse His promise [רד״ק, מצודת דוד].
Two main traditions identify the recipient of this profound vow. One approach points to Abraham, who worried he might face punishment for taking lives during battle. God reassures him that the blessings destined for him remain secure and will not be withdrawn [רש״י]. Furthermore, although taking a life usually disqualifies someone from serving as a priest, God guarantees Abraham's priestly status remains completely intact. This is because it was actually God who fought and defeated the enemies, rather than Abraham himself [אלשיך]. The second tradition identifies the recipient as King David. In contrast to King Saul, whose reign was temporary and ultimately revoked by God, David's royal dynasty rests on an ancient, eternal prophecy [רד״ק, מאירי]. Even if David falters and the nation faces exile, the royal line will never be removed from his descendants [מלבי״ם, מאירי].
The nature of this promised leadership is uniquely described using a priestly title. The primary approach among commentators is that this does not refer to standard priesthood. Instead, it signifies authority, nobility, and royal power, describing a ruler who seamlessly integrates his governance with the service of God [רש״י, רד״ק, אבן עזרא, שטיינזלץ, מאירי]. Conversely, some interpret the promise literally, suggesting that actual priests will emerge from the leader's lineage [רש״י, מצודת דוד].
The eternal nature of this role is established upon a specific divine decree, matter, or custom [רש״י, רד״ק, אבן עזרא, מצודת ציון]. Some link this decree directly to God's spoken promise [אלשיך, מאירי], while others connect it to the Holy of Holies, indicating an appointment over the most sacred spaces of the sanctuary [מלבי״ם]. The leader's status is further defined by a title of righteous kingship, traditionally recorded as two distinct words [מנחת שי], which opens several avenues of interpretation. One perspective views it as a direct continuation of the historical ancient king of Jerusalem, who was also a priest to the Most High God. The promised leader inherits this dual role, ruling over Jerusalem and receiving tithes just as his predecessor did [רש״י, אבן עזרא, מצודת דוד, שטיינזלץ, מלבי״ם]. Another approach suggests the phrasing simply describes the leader's own character. God chooses him because he is a true king of justice who leads with fairness and charity, thereby earning forgiveness for his misdeeds [רד״ק, אבן עזרא, מלבי״ם, מאירי]. Finally, a unique interpretation suggests that the title of righteous king refers to God Himself, the ultimate sovereign upon whose word and promise all earthly kingship is based [מאירי].