From the giving613 website (google this), in the articles tab: “Maaser: The Torah’s Prescription for Wealth” check it out, it’s easy to read (consult a Rav of course):
(bold mine)
“Although anyone who gives Tzedakah has a guarantee from our Torah that he will not be impoverished by doing so, one who properly separates 10% of his income to charity has a guarantee that he will be repaid for every penny that he gives to charity, and that he will become wealthy over time.”
I’m not sure how long “over time” is. It has been 4 years, chesedname, are you wealthy yet?