The answer is that Allah did not praise those who make vows; rather, He praised those who fulfil them—and there is a difference between the two. Allah Most High says: “They fulfil their vows” [al-Insan 76:7]. That is, when they vow something to Allah, they do not neglect it; rather, they carry it out.
There is another view: that what is meant by nadhr (vow) here is all obligatory duties, which are vows, based on Allah Most High’s statement concerning Hajj: “Then let them end their untidiness, fulfil their vows” [al-Hajj 22:29], although they had not made vows. Similarly, Allah Most High says: “Whatever charity you give or vow you make, Allah certainly knows it” [al-Baqarah 2:270]. That is, whatever vow you fulfil after having made it.
As for fulfilling a vow, it falls into five categories, whose explanation will follow.
Our statement, “a legally accountable person binding himself”: a legally accountable person is one who has reached adulthood and is sane. Thus, if a child who has not reached adulthood says, “I owe Allah a vow to do such-and-such,” the vow is not binding, because a child is not legally qualified to impose obligations upon himself, as the pen has been lifted from him.
Our statement, “something he owns that is not impossible”: if he vows something he does not own, the vow is not binding, because the Prophet, peace and blessings be upon him, said: “No son of Adam may make a vow concerning that which he does not own.” (1) Likewise, if he vows to emancipate a free person, it is not binding, because this is something he does not own. And if he vows to fly, it is not binding, because that is impossible.
His statement, “It is valid only from a sane adult”: the evidence is the Prophet’s statement, peace and blessings be upon him: “The pen has been lifted