1)
Where was Moshe commanded to perform this sprinkling?
1.
Rashi asks the question and does not have an answer.
2.
Ramban and Moshav Zekenim: Presumably, it is what the Pasuk means when it writes in Tetzaveh Sh'mos (29:37) "ve'Kidashto oso Vehayah ha'Mizbe'ach Kodesh Kodashim". 1
1
Ramban and Moshav Zekenim: Implying a sanctification over and above all the other Keilim in the Mishkan; and it is logical to say that the Mizbe'ach, which is a K'li for the Korbanos, should not require less than the Keilim (the clothes) of those who served, which required sprinkling. See Oznayim la'Torah who elaborates.
