A vision of the future reveals a time when the leader of the nation will offer a unique sacrifice on behalf of himself and the entire population. This event introduces a significant challenge, as the details of the offering differ completely from the established laws of Moses.
The event is set for the fourteenth of Nissan, the eve of Passover [מצודת דוד, ביאור שטיינזלץ, מלבי״ם], though there is an opinion that it takes place on the first day of the holiday itself [רד״ק]. On this day, the leader is instructed to bring a bull as a sin offering. This creates a major difficulty because the Torah mandates that a holiday sin offering must be a goat, not a bull. The contradictions between the laws of Moses and this prophecy were so sharp that early sages initially sought to suppress the Book of Ezekiel. Eventually, a sage named Hananiah ben Hezekiah managed to resolve these conflicts, but his explanations were lost over time [רש״י].
To understand this departure from the standard laws, the primary approach among commentators is that this is not a permanent change to the Passover sacrifices. Instead, it is a special, temporary instruction for the dedication of the Third Temple [רש״י, מצודת דוד, מלבי״ם]. This offering completes the inauguration period, much like the calf that Aaron offered during the dedication of the Tabernacle. Bringing this sacrifice on Passover eve serves to prepare the leader for the upcoming holiday service [רש״י]. The dedication of this future Temple will be an extended and magnificent event, spanning from the beginning of Nissan until after the holiday of Sukkot [מצודת דוד]. In contrast, another perspective suggests that these differences actually prove that entirely new rules for sacrifices will be established in the future [רד״ק].
The leader is required to provide this sacrifice from his own personal wealth [מצודת דוד]. This requirement serves as a historical correction. Before the sin of the Golden Calf, God's original plan was for Aaron to fund all public sacrifices personally. In the future, when the nation and its leader reach a higher spiritual state, this original ideal will be restored, and the righteous leader will provide the sacrifices for all of Israel [אהבת יהונתן].
The purpose of this specific offering is to provide atonement directly for the leader and the people, as the purification of the altar and the Temple will have already been completed in the preceding days [מלבי״ם]. The specific date of the fourteenth of Nissan also carries a deep historical meaning. Tradition notes that this is the exact day when Cain killed Abel, and this future sacrifice is intended to repair that ancient sin [אהבת יהונתן].