Deuteronomy 23:21-23

21WhenH834 thou shalt vow a vow unto Jehovah thy GodH430, thou shalt not be slack to pay it: for Jehovah thy GodH430 will surely require it of thee; and it would be sin in thee. 22But if thou shalt forbear to vowH5088, it shall beH1961 no sinH2399 in thee. 23That which isH1961 gone out of thy lips thou shalt observe and do; according as thou hast vowedH5087 unto Jehovah thy God, a freewill-offering, which thou hast promised with thy mouth.