A grand, festive event marks the transfer of power from David to Solomon. The nation gathers for a large feast, crowning their new king and appointing their spiritual leadership with broad national agreement and deep joy. The people eat and drink before God, partaking in the meat of the peace offerings that were sacrificed to Him [מצודת דוד]. The narrative waits until this moment to mention the feast, ensuring that the earlier description of the sacrifices and burnt offerings remains uninterrupted [רש"י].
Solomon is crowned a second time, a detail that highlights the stark contrast between his two inaugurations. His first crowning took place in haste under David's direct command, sparked by Adonijah's attempted rebellion. Ordinarily, a king who inherits the throne from his royal father does not require anointing with oil. However, Solomon was anointed the first time specifically to eliminate any doubts among Adonijah's supporters regarding the legitimacy of his rule [רש"י].
The primary approach among commentators notes a fundamental difference between the two events. The initial crowning was a small, almost private affair attended only by the people of Jerusalem and a few key leaders. In contrast, this second coronation is a massive public ceremony witnessed by all the leaders of Israel and the tribal representatives [מצודת דוד, רד"ק, מלבי"ם, ביאור שטיינזלץ]. Furthermore, while the first crowning was driven by immediate necessity, this second event is initiated by the entire nation out of their own free will and profound joy [חומת אנך]. Solomon is anointed to be a ruler according to God's commandment [מצודת דוד, ביאור שטיינזלץ]. The act of anointing is conceptually linked to the idea of drawing the people forward, as a true leader's role is to actively go out before the nation and guide them [רש"י].
During this same monumental gathering, Zadok is appointed and anointed as the High Priest [מצודת דוד, רד"ק, רלב"ג, מלבי"ם, ביאור שטיינזלץ]. He is chosen to replace Abiathar, who was banished from his position after joining the conspirators and participating in Adonijah's anointing [רש"י, רלב"ג, מלבי"ם]. Elevating Zadok also aligns perfectly with David's personal wish, as he preferred Zadok over the priestly family of Eli [ביאור שטיינזלץ]. The close association between the anointing of the new ruler and the new High Priest offers a practical legal lesson regarding the division of war spoils. Just as the High Priest claims half of the priestly gifts for himself while distributing the rest among the other priests, the king takes half of the spoils captured from enemies, leaving the remaining half for the people [רד"ק].