What is the meaning of "Navol Tibol"?
Rashi (citing Targum Onkelos: It means 'You will wither'.
Rashbam: It means 'Your speech will become blurred, when you try to respond to so many people simultaneously, as will theirs, (as each one cries out and receives no response), since you do not have the strength to answer them one after the other.
Targum Yonasan: it means 'You will fall off (like a withered leaf falls off the tree).
Why did Yisro use the word "Gam" twice in his statement?
Rashi: To include Aharon, Chur 1 and the seventy elders.
Targum Yonasan: To include Aharon and his sons and the seventy elders.
Chur had already been killed when they worshipped the Golden Calf - See Rashi 32:6 - which preceded this Parshah? See Sifsei Chachamim.
Why did Moshe judge by himself? Why did he not enlist the help of Aharon, his sons, Chur and the current elders?
Or ha'Chayim: The people wanted only Moshe to judge them, since they had more confidence in him (and in his Ru'ach ha'Kodesh) than in anyone else.
QUESTIONS ON RASHI
Rashi writes that Yisro said that also Aharon, Chur and the seventy elders will wither. But Chur had already died earlier, when they worshipped the Golden Calf (See Rashi in Ki Sissa, 32:6)?
Riva, Hadar Zekenim #1 and Moshav Zekenim #1: Rashi means that, even if Chur was alive, 1 and he and the elders would assist Moshe, [all of] them would not be able to carry the burden. 2
Da'as Zekenim and Hadar Zekenim #2: Here Rashi explains according to the opinion that Yisro came before Matan Torah.
Moshav Zekenim #2: The text should not include Chur. The Mechilta mentions only Aharon and the seventy elders.
This is not applicable later, in Pasuk 23 "ve'Gam Kol ha'Am ... Yavo ve'Shalom", where Rashi explains 'also Aharon, Nadav and Avihu and the elders', and omits Chur.
Riva: Similarly, the Navi writes in Yirmiyah,15:1 "If Moshe and Shmuel were in front of Me [they could not avert My anger from Yisrael]", even though they were no longer alive..
