The Sharia of Moses in the TORA
Part 2 - The 365 Prohibitions of the Tora
157 - INFRINGING ANY ORAL OBLIGATION; EVEN IF UNDERTAKEN WITHOUT AN OATH
In the Sifre we read: “he shall not break his word tells us that one who does not keep his word transgresses two prohibitions - he shall not break his word, and you shall not delay to pay it.”* That is to say, if one vows an offering, or anything similar to an offering, as, for instance, a gift to the Temple treasury, or to charity,** or to a synagogue, or the like, and has failed to fulfill his vow, after the passing of the three festivals (i.e. Passover, Feast of Weeks, and Tabernacles), he is liable under both you shall not delay to pay it, and he shall not break his word. And one who transgresses by doing something which he has bound himself not to do is punished by whipping.
** See Note to Neg. Comm. 155. There Maimonides says that in case of non-fulfillment of a vow to give charity the transgression is immediate, whereas here he says that it does not arise until after the passing of three festivals. Some scholars have suggested that a distinction is to be made between cases in which poor men are at hand and those in which they are not, and that in the latter type of case the three-festival period applies, but in the former there is immediate transgression of the injunction against being slow in paying our offerings.