(כ) וּבָרוּךְ֙ אֵ֣ל עֶלְי֔וֹן אֲשֶׁר־מִגֵּ֥ן צָרֶ֖יךָ בְּיָדֶ֑ךָ וַיִּתֶּן־ל֥וֹ מַעֲשֵׂ֖ר מִכֹּֽל׃
(20) and blessed be God the Most High, who hath delivered thine enemies into thy hand.’ And he gave him a tenth of all.
בעא מיניה רבי מר' ישמעאל ברבי יוסי עשירים שבא"י במה הן זוכין א"ל בשביל שמעשרין שנאמר(דברים יד, כב) עשר תעשר עשר בשביל שתתעשר
Rabbi asked R. Ishmael son of R. Jose, The wealthy in the Land of Israel, whereby do they merit [wealth]? He replied to him; because they tithe, as it is written, 'Asser te'asser (Deuteronomy 14,24) [which means], give tithes ['asser] so that thou mayest become wealthy [tith'asser].
(ד) הצדקה דוחה את הגזירות הקשות וברעב תציל ממות כמו שאירע לצרפית: הגה: והיא מעשרת ואסור לנסות הקב"ה כי אם בדבר זה שנאמר ובחנוני נא בזאת וגו' (טור מגמרא פ"ק דתענית) וי"א דוקא בנתינת מעשר מותר לנסות הקב"ה אבל לא בשאר צדקה (ב"י דכך משמע מש"ס שם):
Charity dispels harsh decrees and famine (&) saves from death as happened at Zarephath: Gloss: (RAMA) This is referring to tithing and one should not test God except in this regard as it was said {Malachi 3,10} "And try Me now herewith" [with tithing] (Tur from the last chapter of Gemara Tanit), and there are those who say that specifically in regards to giving tithes [on produce from Israel] is it allowed to test the Holy One Blessed be His name, but not in regards to other forms of charity. (The Bais Yosef seems to hold this way from Shas there):
(10) Bring ye the whole tithe into the store-house, That there may be food in My house, And try Me now herewith, Saith the LORD of hosts, If I will not open you the windows of heaven, And pour you out a blessing, That there shall be more than sufficiency.
Our Rabbis taught: It is related of King Monobaz that he dissipated all his own hoards and the hoards of his fathers in years of scarcity. His brothers and his father's household came in a deputation to him and said to him,
My fathers gathered for this world, but I have gathered for the future world, as it says, Thy righteousness [zedakah] shall go before thee, and the glory of the Lord shall be thy reward. (Isaiah 58,8)
איזהו עשיר? השמח בחלקו, שנאמר: (תהלים קכח ב): "יגיע כפיך כי תאכל אשריך וטוב לך".אשריך, בעולם הזה .וטוב לך, לעולם הבא.
Who is the rich one? He who is happy with his lot, as it says, "When you eat [from] the work of your hands, you will be happy, and it will be well with you" (Psalms 128:2). "You will be happy" in this world, and "it will be well with you" in the world to come.