What is the extent of a husband's financial liability if he fails to provide support due to poverty (I'sar)?

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If the husband, while being capable (Yasar), neglects his wife's support, he is liable for the entirety of the due support. However, if he neglects support due to actual poverty (I'sar), he is only liable for the support amount corresponding to a poor man's means, as the excess obligation is waived by his state of poverty.