What is the meaning of "Tenah Avon Al Avonam"?
Radak: Avon is the punishment for sin, like "Ki Lo Shalem Avon ha'Emori Ad Henah", "Gadol Avoni mi'Neso" (Bereishis 15:16, 4:13). I.e. punish them for their sin against us.
Malbim: Put this sin, saying that You did this (they pursue and strike only the one whom You already struck) on top of their sins; it should float on top.
What is the meaning of "va'Al Yavo'u b'Tzidkasecha"?
Radak #1: The Tzedakah that You do with Yisrael, and the good that You will do with them, they should not enter it - "u'Val Yir'eh Ge'us Hashem" (Yeshayah 26:10).
Radak #2: This refers to the world to come, like the coming verse explains.
Malbim: Like they want to justify their deeds via attributing injustice to You, so they should not enter Your virtue.
