It says in Abihem Shel Yisrael 'Al HaTorah that even if a man gives charity (Sedaqa) unwittingly, without intending to, it brings him much reward. How can a person give without intending to?
It is like the story of a man who was walking down the road with money in his pocket. He didn't have the slightest intention of giving charity, but what he didn't realize, was that there was a hole in his pocket. As he walked down the road, several coins fell onto the road through the hole in his pocket. A poor man saw them and picked them up. He saw that there was enough money for him to buy bread for the family, which he did.
When he returned home, he and his family did Netilath Yadayim with the Berakha (blessing), sat at the table and recited the blessing of Hammosi on the bread. While they ate, they sang songs of praise and spoke words of Torah at the table. They finished by reciting the Birkath HaMazon (grace after meals).
When, after a long life, the man who lost the money went up to Heaven, they told him that he had received much credit for his act of charity which enabled a family to fulfill so many commandments. The man started arguing with the Beth Din Shel Ma'alah (court on high). "I never intended to give and I have no recollection of it". He was told that it was irrelevant and that he had been credited for doing this important good deed.
If, for performing an act of charity that one had no intention to do, one receives so much reward, how much more so will one receive great rewards for charity that one has the intent to do.
tzedakah, tz'dokah, sedakah, sedaqah