Korban Pesach in Egypt: Did Moshe Modify Hashem’s Command?

Mashkof and Mezuzos

2. This month shall be to you the beginning of months; it shall be the first month of the year to you.
3. Speak to all the congregation of Israel, saying, In the tenth day of this month they shall take every man a lamb, according to the house of their fathers, a lamb for a house;
4. And if the household is too little for the lamb, let him and his neighbor next to his house take it according to the number of the souls; according to every man’s eating shall you make your count for the lamb.
5. Your lamb shall be without blemish, a male of the first year; you shall take it out from the sheep, or from the goats;
6. And you shall keep it up until the fourteenth day of the same month; and the whole assembly of the congregation of Israel shall kill it in the evening.
7. And they shall take of the blood, and strike it on the two side posts and on the upper door post of the houses, in which they shall eat it.

…

21. Then Moses called for all the elders of Israel, and said to them, Draw out and take a lamb according to your families, and kill the Passover lamb.
22. And you shall take a bunch of hyssop, and dip it in the blood that is in the basin, and strike the lintel and the two side posts with the blood that is in the basin; and none of you shall go out from the door of his house until the morning.
23. For the Lord will pass through to strike the Egyptians; and when he sees the blood upon the lintel, and on the two side posts, the Lord will pass over the door, and will not let the destroyer come into your houses to strike you. (Shemos 12)

Tosafos says:
The two mezuzos allude to Moshe and Aharon and the lintel above represents HKBH, the One above. Hashem meant to say: Do this, for in this way because of your merit, Moshe and Aharon, and My merit, they will be redeemed. HKBH thereby teaches his humility, so to speak, by putting Moshe and Aharon first. Moshe said, chalilah that we should put our merit above His. Hence, Moshe reversed the order of the sprinkling to the lintel first and then the mezuzos.
(Moshav Zekenim)