1)
Who says "va'Hadafticha"?
1.
Radak: It is as if Hashem speaks. "Yehersecha" is the Navi's word to Hashem. This is common in Leshon ha'Kodesh, e.g. "Shim'u Amim Kulam" (Michah 1:2).
2)
What is "Ma'amadecha"?
1.
Rashi: It is your service in the Mikdash.
2.
Radak: It is his appointment; the same applies to "Matzavecha".
3.
Malbim: Your standing; you will not have any existence.