If certain uninformed people suppose that one of these forbidden vows has actually met their need—by bringing them wealth, good health, and the like, or by warding off an enemy’s harm and the like—they are deluded.
It is authentically reported that the Prophet (may Allah bless him and grant him peace) forbade making vows, saying, “They do not bring about any good; they merely extract (charity) from a miser.” 1
Thus he deemed the very act of vowing disliked, even though fulfilling a vow is obligatory when the thing vowed is an act of obedience to Allah and His Messenger (peace and blessings be upon him).
The Prophet (peace be upon him) further taught that vows do not bring good; they only draw something out of the stingy—a meaning transmitted from him through several routes even with respect to vows that are pure acts of devotion to Allah. How much more so, then, with a vow that involves polytheism? Such a vow may neither be undertaken nor fulfilled.
Although this practice has become widespread among Muslims, and many people now frequent the graves of the righteous—whether from the Prophet’s family or others—people are duty-bound to obey Allah and His Messenger, to follow the religion with which Allah sent His Prophet, and not to introduce into the faith anything for which Allah has granted no permission. Allah sent the messengers and revealed the scriptures only so that all religion might belong entirely to Him and so that people would worship Him alone, without partner.
As He, Exalted is He, says: “Ask those of Our messengers whom We sent before you: Did We ever appoint gods to be worshipped apart from the Most Merciful?” 2