In the latter part of Parashat Tetzaveh (29:1-37), we read of the procedure by which Aharon and his sons were formally consecrated as kohanim. This procedure entailed the offering of three sacrifices, and the placement of blood and anointing oil on Aharon and his sons. We read that after the blood of the final sacrifice – the eil ha-miluim – was sprinkled on the altar, some of the blood was taken from the altar and sprinkled on the kohanim and their garments, along with anointing oil (29:21). Afterward, the fats of this sacrifice, as well as a portion of the bread that accompanied it, were placed on the altar, and the meat was then eaten by the kohanim (except the chest, which was eaten by Moshe).
The Panei’ach Raza notes that this does not appear to be the sequence followed by Moshe when the time came to consecrate Aharon and his sons. Towards the end of Parashat Tzav, we read of how the commands issued here in Parashat Tetzaveh were executed, but with one difference. Here, God commands Moshe to sprinkle the sacrificial blood and anointing oil on the kohanim and their garments immediately after sprinkling the blood of the eil ha-miluim on the altar. In Parashat Tzav, however, this is done only after the fats of the sacrifice were waved and then placed on the altar. The question thus arises as to why Moshe deviated from God’s instructions and changed the sequence, offering the sacrificial fats on the altar before sprinkling the blood and oil on the kohanim.
The Panei’ach Raza answers that Moshe understood from God’s command that the sprinkling of the blood and oil on the kohanim should be the final stage of the process. After issuing the command to sprinkle the blood and oil, God concludes, “he [Aharon] and his garments shall be made sacred, along with his sons and his sons’ garments.” This conclusion indicates that the sprinkling on the kohanim marked the final stage, whereupon the consecration process would be completed. Moshe therefore understood that he should perform this sprinkling only after he finishes tending to the sacrifice.
The question that remains, of course, is why God issued the command at that point. If His intention was for the sprinkling to be done after the offering of the eil ha-miluim sacrifice was completed, then why did he mention the sprinkling earlier, before instructing that the fats of the sacrifice be burned?
The Panei’ach Raza suggests, quite simply, that the command to sprinkle the sacrificial blood on Aharon and his sons affected the previously mentioned stage – the sprinkling of the sacrificial blood on the altar. Since Moshe would have to later take some of the blood from the altar to sprinkle on the kohanim, he needed to sprinkle enough blood on the altar to ensure that some would remain by the time he was ready to sprinkle the blood on the kohanim. Therefore, immediately after instructing Moshe with regard to the sprinkling on the altar, God mentioned that he would have to later take some blood from the altar to sprinkle on the kohanim, so Moshe understood that he needed to sprinkle a significant portion of blood on the altar.