Commentary for Leviticus 3:8

וזרקו AND [AARON'S SONS] SHALL DASH THE BLOOD THEREOF [ROUND ABOUT] — two applications of the blood are necessary so as to constitute four (cf. Rashi on Leviticus 1:5). He (the priest) dashes the blood with a vessel (Zevachim 55a); it is only the blood of the sin-offering that he applies with his finger (Zevachim 53a).

Only the sin-offering. Concerning the sin-offering brought inside [the Heichal] it is written (4:6): “The kohein shall dip his finger into the blood and he shall sprinkle from the blood” and concerning the sin-offering brought outside it is written (ibid. 34): “The kohein shall take some blood from the sin-offering with his finger and put it atop the corners of the altar.” [Concerning the rest of the offering, however, it says that the kohanim should sprinkle the blood and does not mention “finger”] (R’em). [You might ask:] Why does Rashi not mention this above regarding the peace-offering of cattle? The answer is because it is not so much of a proof above, for perhaps the kohein did sprinkle the blood with his finger, and although Scripture does not write “finger,” we should learn a place where it is not specified from where it is clearly written — regarding the sin-offering. Therefore, Rashi waited until the end of all the sacrifices and since none of them mentioned “finger” except the sin-offering, perforce [only for the sin-offering was the blood sprinkled with the finger] (Gur Aryeh).