DEUT1293 Jacob took a vow voluntarily to give one part in ten for Heaven's purposes. [Genesis 28:22]. By the Torah's command, his children, the people Israel fall heir to that vow; so to speak, it continues in existence, for us to fulfill. And Scripture warns ... [this verse]. Do not wait until you have to part with your wealth "on demand," under duress. Whenever you can contribute to a deserving cause – to support the poor, to assure Torah study, or whatever – – and you have "tithe the money" to give, give it readily and cheerfully. For in any case Heaven will get its due from you. As the Mishnah puts it, the Holy One would tell wicked farmers in ancient Israel, "The things you did toward Me in the sunny season – – – you did not set apart t'rumah and tithes--will rob you of rain [in the rainy season]" (Midrash Sifre, Deuteronomy §40). Dare to hoard the tenth part for charity, and you will be left with nothing but guilt for your troubles.