What do we learn from "Loveh Rasha v'Lo Yeshalem"?
Avos 2:9: Borrowing from a person [and not paying] is like borrowing from Hashem. Rashi (there) - this is because in the end, Hashem will pay [if the borrower does not - found to be 37:21:3:1].
Tosefta (Chagigah 1:7): If one did not bring Chagigah during the Regel, he has no obligation to bring it afterwards.
Radak: A Rasha's Midah is not to pay his loan, and all the more so he does not give what is his!
Malbim: The Rasha does not trust in Hashem; he does not pay, amidst concern lest his money be finished off.
What is "Chonen v'Nosen"?
Radak #1: Chonen is like Nosen - "Asher Chanan Elokim" (Bereishis 33:5). The matter is repeated in different words to increase the giving, time after time.
Radak #2: Chonen is mercy; v'Nosen teaches that he also has the Midah of generosity.
Malbim: Chonen is lending others; v'Nosen is giving Tzedakah for a gift.
What do we learn from "v'Tzadik Chonen v'Nosen"?
Rashi (from Pesikta d'Rav Kahana 28): [If a Rasha does not pay his debt,] Hashem, the Tzadik of the world, is gracious, and pays the lender from His.
Radak: A Tzadik is opposite. He gives what is his - it goes without saying that he pays his loan!