1)
Who are the Nesinim?
1.
Rashi: They chopped wood and drew water for Yisrael. This was their income.
2.
Ibn Ezra: They are the heads of Giv'on and its villages. Yehoshua (9:27) gave them for Beis Elokav 1 , therefore they are called Nesinim. Even though it says below ( 8:19) that David and the Sarim gave them for Avodas ha'Leviyim, it means that he sustained what was done. Or, from that day they were called Nesinim; before, they were called Giv'onim.
1
There it says "la'Edah ul'Mizbach Hashem." (PF)
