The Right Hand and the Finger in the Blood Rite

"And you shall take of the blood of the bull and put it upon the horns of the altar with your finger" (Exodus 29:12). Our Rabbis taught: "with his finger, and he shall take" (Leviticus 4:34) teaches that receiving the blood may be done only with the right hand. "With his finger, and he shall put" (Leviticus 4:34) teaches that placing the blood may be done only with the right hand. Rabbi Shimon said: but was a "hand" mentioned in connection with receiving? Since no "hand" was mentioned regarding receiving, if he received with the left hand it is valid. Abaye said: they disagree as to whether a verse is expounded in reference to what precedes it and what follows it. Abaye said: this ruling of Rabbi Elazar son of Rabbi Shimon contradicts both his father and the Rabbis, for it was taught: Rabbi Elazar son of Rabbi Shimon says: wherever "finger" is mentioned regarding receiving, if he deviated in the receiving it is invalid, but in the placing it is valid; and wherever "finger" is mentioned regarding placing, if he deviated in the placing it is invalid, but in the receiving it is valid. And where is "finger" mentioned regarding placing? As it is written, "and you shall take of the blood of the bull and put it upon the horns of the altar with your finger." He holds that a verse is expounded in reference to what precedes it, but not to what precedes that, nor to what follows it. Rabbah said in the name of Rabbi Shimon ben Lakish: wherever "finger" and "priesthood" are mentioned, it means only the right hand. "Finger" does not require "priesthood," but "priesthood" requires "finger." Then why do I need "priest" mentioned at all? To teach that he must be in his priesthood [wearing the priestly garments].