On this daf, we find that giving maaser makes one rich.
The Chofetz Chaim wrote that profaning Shabbos can even disrupt the many segulos that the sages say are the result of doing good things. For example, one who gives maaser but is not shomer Shabbos should not expect the maaser to enrich him. This is like a man who ate a balanced and nutritious meal but then followed it up with a dose of poison. We all understand that although nutritious food generally makes one healthy, the meal will not neutralize the effect of the poison in any way.
One time, there was a big gathering of rabbonim in St. Petersburg that the Chofetz Chaim attended. While there, he was visited by a group of wealthy businessmen, who came to him seeking a brocha.
One of the visitors was not actually observant, but he was so profoundly moved by the meeting that he gave the Chofetz Chaim a huge sum of money for his yeshiva in Radin.
The gadol clasped the donor’s hand in his and said, “Ay! Such a precious hand which gave such a generous gift to tzedakah! What a pity that it perpetrates chillul Shabbos!” As he spoke these words, the gadol started to weep bitterly, all the while holding tightly to the hand of the gevir.
The words uttered by the Chofetz Chaim shook the man at his foundations. He burst into tears and pleaded, “Rebbe, from now on I will keep Shabbos! But please allow me to violate it just this week. I have some pressing business.”
The Chofetz Chaim responded gently, “My dear child! The Shabbos is not mine that I can give you permission to violate it for monetary gain. The Shabbos belongs to Hashem, and we must keep it no matter how much money we stand to lose.”
From that moment, the businessman was a shomer Shabbos (Meir Einei Yisroel).