1)
Why does the Torah use the double expression "Isaron Isaron"?
1.
Menachos, 87b: It teaches us that there had to be a measure of half an Isaron in the Beis-Hamikdash. 1
1
For the Chavitei Kohen Gadol, which was brought in halves, half in the morning and half in the afternoon (Torah Temimah)..
2)
Why does the Torah add the (otherwise superfluous) words "le'Shiv'as ha'Kevasim"?