הלכה על במדבר 29:13

That is that He commanded to offer an additional sacrifice on the holiday of Sukkot. And that is His, may He be exalted, saying, "You shall offer a burnt-offering" (Numbers 29:13). And that is the additional offering of the holiday. (See Parashat Pinchas; Mishneh Torah, Daily Offerings and Additional Offerings 10:3.)