In this week’s parsha we are commanded: עשר תעשר את כל תבואת זרעך – “To take ma’aser [tithes] from all our crops” (14:22). The Gemara in Ta’anis (9a) interprets our pasuk by playing on the similarity between the letter’s “shin” and “sin.” It renders the wordsעשר תעשר in our pasuk as עשר בשביל שתתעשר – take ma’aser and you will become rich. What source is there for the Gemara’s teaching that taking ma’aser will make a person wealthy?
The Vilna Gaon notes that the Gemara (Bava Metzia 31a) generally understands a doubled verb as requiring a person to repeatedly do the action referred to as many as 100 times. In other words, he is not absolved from his obligation by performing it once. He must repeatedly do the mitzvah as many times as is necessary. In this light, our pasuk, with its doubled command to separate maser (עשר תעשר) should be understood as requiring a person to take ma’aser from his money as many as 100 times. However, the Gemara in Kesubos (50a) records that Chazal decreed that a person shouldn’t give more than one-fifth of his money to tzedokah. If so, the Gemara in Ta’anis questioned how a person could be permitted to tithe by giving one-tenth of his money even three times, as this would require him to give more than one-fifth of his assets to tzedokah.
To resolve this concern, the Gemara answered that the Torah guarantees that a person who does so will become rich and will have enough money to continue tithing – even 100 times – without ever falling below the threshold of having given one-fifth of his original possessions to tzedokah.
