What is the meaning of "Im Amarti Asaperah Chemo"?
Rashi: Asaf said, if I thought to tell everything like it is, I would say...
Radak: Asaf says so, or every Chasid in every generation in Galus. If I would say this claim, like they say (that Hashem does not know - verse 11), I would betray You. "Hinei" belongs after Dor Banecha; it is written out of place. There are many verses like this, e.g. "u'Misped El Yod'ei Nehi" (Amos 5:16; it means, v'Yod'ei Nehi El Misped. "Mekom Sham Kever" (Yechezkel 39:11) is like Mekom Kever Sham.
Malbim: If I will express this great question (why Resha'im prosper), if I will say it like it is, the generation will betray Hashem and deny [Him], and I will cause the Rabim to sin.
What is the meaning of "Hinei Dor Banecha Vagadti"?
Rashi: I would make them (say that they are) traitors and Resha'im.
Malbim: Refer to 73:15:1:3.