Numbers 28:10

עלת שבת בשבתו lit., THE BURNT OFFERING OF A SABBATH ON ITS SABBATH — and not the burnt offering of this Sabbath on another Sabbath. Take the case that one had not offered the sacrifice on this Sabbath, I might think that he might offer two on the following Sabbath! However, it states “on its Sabbath’, thus showing that if its day (the Sabbath on which it had to be brought) be past, its (that Sabbath’s) offering is cancelled (Sifrei Bamidbar 144:2). על עלת התמיד BESIDES THE CONTINUAL BURNT OFFERING — these two lambs are additional offerings for the Sabbath besides (על) those two lambs of the continual burnt offering. And this tells us that these additional offerings must be brought only between the two continual offerings (Sifrei Bamidbar 144:2). Similarly in the case of all additional offerings it is stated that they are to be brought על עלת התמיד to point to this deduction.

עֹלַ֥ת שַׁבַּ֖ת בְּשַׁבַּתּ֑וֹ עַל־עֹלַ֥ת הַתָּמִ֖יד וְנִסְכָּֽהּ׃ {פ}

this is the burnt offering of every sabbath, beside the continual burnt offering, and its drink offering.