Is it permissible to fulfill a vow by slaughtering on Eid al-Adha and feeding one's family from it, and what are the conditions for a vow to be valid?

The vow of obedience must be fulfilled, according to the Prophet's (PBUH) saying: "Whoever vows to obey Allah, let him obey Him." It is permissible to fulfill it at any time, and it does not substitute for the Udhiyah (sacrifice).

The one who made the vow should not eat from his vowed sacrifice. If he eats from it, he must pay its value to the poor, because the animal vowed for the poor is designated for them. His immediate family is included among the beneficiaries unless he intended to exclude them.