Is the husband's failure to fulfill his vow to fast for two consecutive months—a vow he made at the age of twenty-five and has not yet fulfilled, being now thirty-seven—considered a reason for the non-acceptance of supplications, and what are the consequences of not fulfilling this vow?

One must fulfill a vow of obedience to Allah, for the Prophet, peace and blessings be upon him, said: "Whoever vows to obey Allah, let him obey Him." Vows are disliked (makruh). If the vow was specific, such as fasting for two designated months, then it is obligatory to fulfill it immediately if one is able. Failure to do so incurs sin, and according to some scholars, necessitates both expiation for breaking an oath (kaffarat yameen) and fasting. However, if the vow was not time-specific, it is recommended to fulfill it promptly. Disobeying a vow may be a reason for prayers not being answered. If the person who made the vow is unable to fulfill it, there are detailed rulings concerning that.