Moses
Numbers 28:21ESV·traditional attribution
a tenth shall you offer for each of the seven lambs;
Matthew Henry Presbyterian @wholebiblehenry
Here is, I. The appointment of the pass-over sacrifices; not that which was the chief, the paschal lamb (sufficient instructions had formerly been given concerning that), but those which were to be offered upon the seven days of unleavened bread, which followed it, Num 28:17-25.
Commenting on Numbers 28:16-31
Keil & Delitzsch Lutheran @keilanddelitzsch
Num 28:16-22 The same number of sacrifices as at the new moon were to be offered on every one of the seven days of the feast of unleavened bread (Mazzoth), from the 15th to the 21st of the month, whereas there was no general festal offering on the day of the Passover, or the 14th of the month (Exo 12:3-14).
Commenting on Numbers 28:16-22