How is "Pe'ulas Tzadik l'Chayim"?
Rashi, from Devarim Rabah 2:13: Shlomo made the Mikdash for the life of Yisrael, and an atonement for them.
R. Yonah: Whatever he does, both in Mitzvos and toil to earn his money, be it much or little, all his acts are for life. His toil for money is lest he stretch his hand to unjust gain, and in order to honor Hashem from his wealth (3:9), and so he can dedicate his Nefesh to Shamayim's work, elevate Yir'ei Hashem and empower those who make His name known. Their desires are for Shamayim; the purpose of their toil is not for pride and to rule over people.
Malbim: Engaging in a matter and preparing means for it, this is called Pe'ulah. If he finishes it, it is called Ma'aseh. E.g. seeding, plowing and all acts before [grain grows] are Pe'ulah; when the grain is finished, this is Ma'ase. A Tzadik, also his Pe'ulos, i.e. the means to prepare the purpose, lead to life, and all the more so the purpose - the Ma'aseh of Tzedek itself. The Rasha, also his finished grain - the purpose of his Ma'aseh - is for sin and lack. It is a false purpose!
How is "Tevu'as Rasha l'Chatas"?
Rashi, from Devarim Rabah 2:13: Menasheh's bringing an idol into the Mikdash (Divrei ha'Yamim II, 32:7) was a sin.
R. Yonah: The wealth and added money that a Rasha gathers, even if it is not from theft 1 , it is all sin and a stumbling block. It helps his evil and strengthens evildoers like himself. He attains his full desires amidst his evil, and puts his fear and authority on Tzadikim. His wealth adds to his pride, and he trusts in his wealth and not in his Maker. Even if his wealth causes only that people honor him, it elevates To'avas Hashem, strengthens His haters and raises those who lower the honor of His servants. This suffices to consider it Chatas! This is the reply to the Dal, who thinks that his poverty is his trouble - if he will choose to go in the ways of Tzadikim, all his deeds will be for life; he will not fear his poverty. If he will go in the counsel of Resha'im, and covet wealth, his poverty is better for him, lest his wealth be a stumbling block for him.
Malbim: Refer to 10:16:1:3.
R. Yonah: You cannot say that this discusses gathering wealth from theft. If so, it should have said Tevu'as Rasha Chatas [in place of l'Chatas]. Also, often the grain and wealth of a Rasha is from his toil.