Among the different sacrifices that have the blood of the animal sprinkled on the outer altar as part of the sacrificial service, some of them require four placements of blood on the altar, some need “two that are four” (i.e. pouring the blood on two corners of the altar so that the blood is poured on all four sides of the altar) and some require only a single placement of blood. All of these laws will be explained in detail in the fifth perek (=chapter) of Masechet Zevahim.
The Gemara on today’s daf (=page) brings a number of different halakhot relating to the laws of sprinkling blood. One example is the teaching brought in a baraita in the name of Rabbi Yehudah haNassi, regarding what to do with the remainder of the blood after the sprinkling has been done. Basing himself on the passage that appears in the case of a sin-offering brought from fowl (hatat ha-of, see Vayikra 5:9), Rabbi Yehudah haNassi teaches that the blood of other similar korbanot must also be poured into the drain at the base of the altar – the yesod ha-mizbe’ah.
This is the explanation of the Gemara as presented by Rashi and most of the other commentaries. In his commentary to Masechet Tamid, the Ra’avad offers an alternative explanation to the Gemara in the name of Rabbenu Efraim. According to their approach, no sacrifices – with the exception of sin-offerings where the Torah specifically requires that the remaining blood be poured into the drain in the base of the altar – require that the remaining blood be disposed of in this way. They believe that the Gemara uses this passage to teach that the sprinkling of the blood of these sacrifices must be done only in a place where the altar has a base to it, which excludes the south-east corner of the altar.