מלאכי, פרק ג׳, פסוק י׳

God presents a direct challenge to the people, accompanied by a unique promise: full observance of the commandment to give tithes will bring unprecedented, supernatural abundance. The primary approach among commentators is that bringing all the tithes into the Temple storehouse is meant to provide for God's servants. By ensuring that there is an abundant supply of food and livelihood for the priests and Levites working in the Temple, the people support those considered to be members of God's own household [רש״י, מצודת דוד, ביאור שטיינזלץ, צאינה וראינה, מצודת ציון, מלבי״ם]. Delivering these tithes properly, without stinginess, serves as a direct act of repentance, correcting the past sin of withholding offerings from God [רד״ק, אבן עזרא].

Within this instruction is a highly unusual invitation. God tells the people to test Him right now to see if He will reward their obedience [מצודת ציון, מצודת דוד]. This creates a difficulty, as the Torah explicitly forbids testing God. Commentators explain that despite this general prohibition, God specifically permits and even encourages people to test Him when it comes to tithes and charity [ביאור שטיינזלץ, צאינה וראינה]. This serves as the foundation for the principle of giving a tenth of one's wealth specifically in order to become rich [צאינה וראינה]. Offering a deeper understanding, [מלבי״ם] distinguishes between a forbidden test and a permitted trial. A forbidden test involves seeking out hidden forces beyond the natural world. However, because God has already explicitly promised to open His storehouses and provide a miraculous blessing, checking to see if He keeps His word is not a forbidden test, but rather a permitted verification of a guaranteed promise.

In return for their faithfulness, God swears an oath to grant massive prosperity [מצודת דוד]. He promises to open the windows of heaven, a metaphor for pouring down rains of blessing and great wealth [אבן עזרא, צאינה וראינה, מצודת ציון]. This outpouring is described as a continuous, flowing stream of abundance that goes far beyond merely satisfying basic needs [מצודת ציון, אבן עזרא, ביאור שטיינזלץ]. While a blessing that comes through natural means has a limit where one can eventually say it is enough, God's blessing in this context is miraculous and completely boundless [מלבי״ם]. The commentators emphasize the sheer magnitude of this prosperity: crops and wealth will multiply to the point that the threshing floors will lack the space to hold them [מצודת דוד], and normal vessels and storehouses will not be enough to gather everything [רד״ק, צאינה וראינה]. The abundance will flow so endlessly that the people themselves will eventually have to ask for it to stop, crying out that they have enough [רד״ק].