Rav Avraham Yosef, the son of Rav Ovadia זצ״ל, made an interesting observation regarding מעשר כספים, the obligation to give one tenth of our income to צדקה. Although there are three opinions on the subject, Torah obligation, rabbinic obligation, or custom, Rav Yosef emphatically claims it is a rabbinic obligation for the simple reason that the מעשר that we take for fruits and vegetables, are also rabbinic nowadays. When the majority of Jews were farmers, the tithing was taken from crops. For others whose income may have come from commerce, the מעשר was paid with money. Rav Yosef goes on to say that because it is rabbinical, families who are struggling and have difficulty in "finishing the month", they should view their charity as supporting the members of their households. They do not need to give outside of their homes. The obligation to give ten or even twenty per cent of income, applies only to those who can afford it. His opinion makes sense and is worth sharing. But, on the other hand, we should bear in mind the importance of charity and the power it gives. The rabbis say, צדקה תציל ממות, charity saves one from death. One needs to do careful soul searching to be certain that this Mitzva is not taken lightly.