And the 41st mitzvah is that we are commanded to bring an offering each Sabbath in addition to the daily offerings.1 This is the Sabbath musaf offering.
The source of this commandment is G‑d's statement2 (exalted be He), "On the Sabbath day [you shall present] two [additional] yearling sheep."
The order of how it is brought is explained in the 2nd chapter of Yoma3 and in Tamid.