Chabad.org — English translation + Rashi
Torah Temimah points to Yoma 59a (unit 7; single primary locus per emergency Core plan).
E-Daf.com — Yoma 59a
HebrewBooks / Shas PDF
English: “To the base of the burnt-offering altar” — residual blood of outer chatas offerings was poured on the southern base.
Southern base for outer chatas residues — leftover blood of the nasi’s outer chatas is poured at the southern side of the altar base.
After the applications to the horns, the remaining blood of the nasi’s chatas (an outer chatas) is poured specifically onto the southern portion of the altar base. This locates the shefichat shirayim for all outer chatas offerings at that side of the yesod.