Leviticus 1:5

הכהנים …‎ושחט …והקריבו AND HE SHALL SLAUGHTER … AND THE PRIESTS SHALL OFFER [THE BLOOD] — All the rites from “receiving the blood in a vessel” (which is implied in והקריבו) and onwards are the duty of the priesthood. This teaches about the slaughtering that it is valid even if performed by a layman (Sifra, Vayikra Dibbura d'Nedavah, Section 4 2; Zevachim 32a). '‎לפני ה‎‎‎ means in the forecourt. והקריבו AND [THE PRIESTS] SHALL OFFER [THE BLOOD] — This must refer to “receiving the blood in a vessel”, since this is the first rite mentioned after the slaughtering of the animal, but really it implies the bringing of the blood to the altar; we thus learn that both of them (receiving of the blood and bringing it to the altar) as well as all the succeeding rites are priestly duties (cf. Zevachim 4a): בני אהרן — One might think that these duties may be performed also by חללים (priests who have lost their priestly status for reasons connected with their birth or marriage)! Scripture, however, adds הכהנים, the priests (i.e. they must not only be descendants of Aaron but also “priests” — fit for priesthood, and חללים are excluded from priestly functions) (Sifra, Vayikra Dibbura d'Nedavah, Section 4 6). את הדם …וזרקו את הדם [AND THE PRIESTS … SHALL OFFER] THE BLOOD AND SHALL SPRINKLE THE BLOOD — Why does Scripture use the word דם twice (instead of saying והקריבו את הדם וזרקוהו)? In order to include in the command of sprinkling also the blood of an עולה which has been commingled with blood of the same kind of sacrifice (i. e. with the blood of another burnt offering) or with that of a different kind (that of a peace — offering or a guilt — offering). One might think that this law applies also if it has been commingled with that of sacrifices unfit for sacrifice or with that of sin — offerings whose blood has to be sprinkled in the “Interior’ (the Holy Place) or with that of sin — offerings whose blood has to be sprinkled outside (in the court), although these (i. e., the blood of the (חטאות פנימיות וחיצוניות) has to be sprinkled above the red line (that marks the division between the upper and the lower halves of the altar) and it (the blood of the עולה) below! Scripture, however, states of an עולה in another place (v. 11) ‘‘[and he shall sprinkle] its blood (דמו)” (cf. Sifra, Vayikra Dibbura d'Nedavah, Section 4 7-8; Zevachim 81). וזרקו AND [THE PRIESTS] … SHALL DASH [THE BLOOD ROUND ABOUT] — He (the priest) stands below and dashes the blood from the vessel upon the altar wall below the red line over against the two diagonally opposite corners (the north — east and the south — west corners so that there is blood on the four sides). That is what Scripture means when it says, סביב, “round about” — that the blood shall be put upon all the four sides of the altar. Or I might think that it means he (the priest) shall place it (the blood) right round the altar as a line! Scripture, however, states, וזרקו, “and they shall dash [the blood]” (i. e. fling it; cf. Exodus 9:8; thus implying that he must be standing some distance away), and it is impossible to put it right round the altar by flinging it against it. — The explanation given above as to how it was actually done is arrived at by the following argument: If we go only by the meaning of the word וזרקו alone, one might have thought that it would suffice with one “flinging” only (that we need merely fling the blood against one side of the altar)! Scripture, however, adds סביב, “round about”! How then can this be done? He makes two flingings but in such a manner that they virtually constitute four, as stated above). (Sifra, Vayikra Dibbura d'Nedavah, Section 4 9) אשר פתח אוהל מועד {AND THEY SHALL SPRINKLE THE BLOOD ROUND ABOUT THE ALTAR} THAT IS BY THE ENTRANCE OF THE APPOINTED TENT — but not at times when it (the appointed tent) had already been dismantled, even though the altar itself were still in position, for then it is not by the entrance of the appointed tent (Sifra, Vayikra Dibbura d'Nedavah, Section 4 14).

וְשָׁחַ֛ט אֶת־בֶּ֥ן הַבָּקָ֖ר לִפְנֵ֣י יְהֹוָ֑ה וְ֠הִקְרִ֠יבוּ בְּנֵ֨י אַהֲרֹ֤ן הַכֹּֽהֲנִים֙ אֶת־הַדָּ֔ם וְזָרְק֨וּ אֶת־הַדָּ֤ם עַל־הַמִּזְבֵּ֙חַ֙ סָבִ֔יב אֲשֶׁר־פֶּ֖תַח אֹ֥הֶל מוֹעֵֽד׃

And he shall kill the bullock before the Lord: and the priests, Aharon’s sons, shall bring the blood, and sprinkle the blood round about upon the altar that is by the door of the Tent of Meeting.