Rashi: This is like one who grabs his brother in his father's house, saying 'you are rich in Torah.'

Radak: He grabs him via his garment to speak to him and request this. It is not literally his brother, rather, "Beis Aviv" - one from his family, for whom he feels affinity.

Malbim: In earlier days, everyone used to strive to be chosen for a leader. It was honor for him and his whole family. Now it is opposite (people decline to be leaders, like verse 7 will say).

Radak citing Shabbos 119b: (Even when Yerushalayim stumbled, faithful people did not cease from it!) You know matters that others seek to cover up [their ignorance about them] like with a garment. Therefore, you will be our leader.

Rashi #1: [Torah] is clear in your hand, like a garment - you will teach to us!

Rashi #2: You have a garment to clothe the naked.

Radak: Since you are dressed in nice garments, and you look important, and people will favor you, you will be a leader for us. You will rebuke one whom it is proper to rebuke.

Malbim: You are dressed in honorable garments. It is proper for you to be a leader over us. It will be honor for you and your family. This shows the lowliness of the nation, that a garment makes someone among the honored.

Radak citing Shabbos 119b: You know matters that others understand only after stumbling in them. (Therefore, you will be our leader.)

Rashi #1: We stumble in Isur or Heter, Tum'ah or Taharah - you know it, to rule for us.

Rashi #2: What I lack, i.e. bread, you have, to supply me. Therefore, you will be an officer over us.

Radak: This pitfall in which we stumble, that we do not fear due to our fellow men, will be under your hand and authority [to fix it].

Radak, from Targum Yonasan: The tax that Nochri kings used to impose on us, like it says about Pharaoh Necho "va'Yiten Onesh Al ha'Aretz Me'ah Kikar Kesef v'Kikar Zahav" (Melachim II, 23:33).

Malbim: The rampant brazenness, and the evil of the rule of Ne'arim, you can fix them. If you refuse to be appointed, your hands caused the stumbling!