Rashi: An Am ha'Aretz always needs a Chacham.

R. Yonah: This returns to discuss wealth mentioned above. The poor fear an Ashir, because they need him. Also, "v'Ohavei Ashir Rabim" (14:20, 19:4), so they fear him.

Malbim: In the old days, Ashirim lent to Aniyim with Ribis. The law was, if he cannot pay, the lender could take him, his wife and children for slaves and subjugate him with a staff, as he wanted. Via the Ribis, the Dalim faltered and became Rashim, who are more destitute than Dalim. Dalim Nisdaldelu (became poor), "vela'Rash Ein Kol" (Shmuel II, 12:3; he has nothing), and became slaves. Sometimes this aroused the borrowers to rebel, and they killed the rich and took great vengeance. Sometimes officers needed to enact to pardon the loans or that the country's treasury would pay, to quash the revolt. At these times, the rich who did not lend with Ribis, rather, they gave Tzedakah to the poor, the nation greatly honored and blessed them. Our verse teaches that "Ashir b'Rashim Yimshol", because "v'Eved Loveh l'Ish Malveh." Refer to 22:9:1:4.

Sanhedrin 31b: The lender can force the borrower (to go to be judged where he wants, here or in the Beis ha'Va'ad).

Bava Basra 10a: "Malve Hashem Chonen Dal" (19:17) - if not for the verse, it would be forbidden to say such a thing! Hashem considers Himself to be like a borrower (who is like a slave) to one who gives Tzedakah.

Bava Basra 51a: If Reuven borrowed from his slave and freed him, or borrowed from his wife and divorced her, the freed slave or ex-wife has no claim against him. He can say 'I only pretended to borrow in order to get him or her to show the money that he or she took from me!' He is believed, for "Eved Loveh l'Ish Malveh" (people are very reluctant to borrow; it is unlikely that he truly borrowed money ¹ !).

R. Yonah: Also people who are not poor, often they need to borrow from Ashirim, and they are subjugated to him, and show favor to him.

Malbim: Refer to 22:7:1:2.