Is it obligatory to give out the entire amount vowed to Allah despite being in dire need of it, or is it permissible to give out a quarter of the vowed amount without sin?

A contingent vow is disliked because it extracts from the stingy, but it must be fulfilled in the manner in which its maker vowed it, if the contingency occurs. It is not permissible to change it, due to Allah's saying: "And let them fulfill their vows," and the Prophet (peace be upon him) saying: "Whoever vows to obey Allah, let him obey Him." Therefore, the full vowed amount must be given out.