Komentaryo sa Exodo 30:10: Rashi, Chizkuni, Rashbam & Kli Yakar

וכפר אהרן AND AARON SHALL MAKE EXPIATION — This refers to the placing of the blood upon the horns of the altar.

וכפר אהרן על קרנותיו אחת בשנה, “and Aaron is to perform atonement rites once a year on its horns (corners); this does not mean that no blood is to be sprinkled on the horns of this altar except once a year; after all the Torah wrote (Leviticus 4,7) that if the High priest has committed an inadvertent sin that he must atone for this by means of the blood of a bull, by sprinkling some of it on the horns of this altar, and the same procedure is also decreed to be performed in another instance mentioned in Leviticus 4,18,; but in our verse the Torah refers to the Day of Atonement when the High Priest performs all the rites pertaining to atonement for the entire nation, after having first made sure that his own sins and those of his family had been atoned for. This ritual had to be performed every year on the same day, whereas the other two rituals we cited may not have been called for many years.

אחת בשנה, on the Day of Atonement. This was confirmed in Leviticus 16,18 ויצא אל המזבח אשר לפני ה', “he shall go out to the altar that is before Hashem, etc.” On all the other days of the year the golden altar was used only for incense burning.

אחת בשנה ONCE IN THE YEAR — On the Day of Atonement. This is what is said in the section אחרי מות, which describes the sacrificial service on that day, (Leviticus 16:18) “And he shall go out unto the altar that is before the Lord and make an expiation upon it”.