Vows do not change
 qadaa’ (divine decree)
Question

                Assalamu Alaikum
     Please help me to understand. I need to know the meaning of the following
      Hadith:
Narrated Abu Huraira:
   The Prophet said (PBUH) (that ALLAH said), "Vowing does not bring to
      the son of Adam anything I have 
     not already written in his fate, but vowing is imposed on him by way of
      fore ordainment. Through vowing I make a miser spend of his wealth"
  This Hadith is from Al-Qadar. Please help me with this meaning. I have
      also sent you a question asking you to please explain the meanings
  of some of the Surahs and ayats that we are supposed to pray. The
      reference number 2241. Is it possible for you to please answer that question.
   May ALLAh guide and protect you for your kindness and help and may he
      bless our Prophet Muhammad (PBUH) ,Wassalam.
Praise be to Allah.The hadeeth you mention was narrated by Imaam al-Bukhaari (may Allaah have
    mercy on him) in his Saheeh from Abu Hurayrah from the Prophet 
 (peace and
    blessings of Allaah be upon him), who said (that Allaah said): “Vowing does not bring
    to the son of Adam anything that I have not already written in his Qadar (preordainments),
    but vowing is imposed on him by way of preordainment. Through vowing I make a miser spend
    of his wealth.” (Saheeh al-Bukhaari, no. 6119)
Ibn Hajar (may Allaah have mercy on him) said in his commentary on this
    hadeeth:
“Ibn ‘Umar said: ‘The Prophet 
 (peace and blessings of
    Allaah be upon him) forbade the making of vows.’ … A clear statement prohibiting
    vows came in the report of al-‘Alaa’ ibn ‘Abd al-Rahmaan from his father
    from Abu Hurayrah, recorded by Muslim in the words ‘Do not make vows,’ and in
    the phrase ‘(Making vows) does not bring forward anything or delay anything [i.e., it
    has no effect whatsoever],’ and in the report of ‘Abd-Allaah ibn Murrah,
    ‘It does not change anything,’ – which is more general. A similar phrase
    was reported in the hadeeth of Abu Hurayrah: ‘Vowing does not bring to the son of
    Adam anything that I have not already written in his Qadar (preordainments)…’
    Ibn al-Atheer said in al-Nihaayah: ‘The point of the hadeeth is that he told
    them that this thing (making vows) does not bring any immediate benefit or turn away any
    immediate harm, and it does not change what has been decreed. Thus he said, Do not make
    vows, as you know that you cannot get, or turn away, anything by means of vows that Allaah
    has not already decreed for you. If you make a vow then fulfill it, because whatever you
    have vowed becomes obligatory for you.’ (Then Ibn Hajar quotes the opinions of a
    number of scholars on the reason why making vows is prohibited): … The reason may be
    that the person who makes a vow does not do so in order to draw closer to Allaah, but will
    only do so if he gets what he wanted, as if this is an exchange, which corrupts his
    intention to draw closer to Allaah. This interpretation is indicated by the words,
    ‘It does not bring any good,’ and ‘Vowing does not bring to the son of Adam
    anything that I have not already written in his Qadar (preordainments).’ This is a
    clear statement as to why vows should not be made. The phrase ‘it does not bring any
    good’ means that the end result will be no good, and it might be too difficult to
    fulfil the vow, or it might mean that (the vow) will not bring about good if it has not
    been decreed for him…. Al-Nawawi said: ‘The phrase “it does not bring any
    good” means that it will not stop anything that has already been decreed, as is clear
    from the other reports.’ … (Then Ibn Hajar quotes from Ibn Daqeeq al-‘Eed),
    saying that he described the difference between nadhr al-mujaazaah (vow of
    repayment, one in which an act of worship is promised in return for a favour), which is
    forbidden, and nadhr al-ibtidaa’ (vow of initiative, where one does the
    promised act of worship first, without waiting to see if the favour is granted or not),
    which is a pure act of worship.”
In al-Mufahhim, al-Qurtubi confirmed the idea that the ahaadeeth
    forbid nadhr al-mujaazaah: ‘This refers to a situation where a man might say,
    for example, “If Allaah heals this person who is sick, I will give such-and-such in
    charity.” The reason why it is disliked is that he postpones doing the act of worship
    mentioned, and makes it conditional upon getting the desired result. This makes it quite
    clear that he does not have the sincere intention of drawing closer to Allaah, because he
    has clearly stated that his approach is that of giving something in return for something.
    It is quite clear that if the sick person is not healed, he will not give the charity
    which is conditional upon the sick person’s recovery. This is the attitude of the
    miser, who does not give anything of his wealth except in exchange for some immediate
    return, usually something that is worth more than what he is prepared to give. This is
    what is referred to in the hadeeth: “Through vowing I make a miser spend of his
    wealth.” To this could be added the point that there is an ignorant belief that
    making a vow guarantees that one will get the desired result, or that Allaah will do what
    a person wants because of the vow. Both notions are addressed in the hadeeth: “Vowing
    does not bring to the son of Adam anything that I have not already written in his Qadar
    (preordainments).”’ Concerning the aayah (interpretation of the meaning): “They
    (are those who) fulfil (their) vows…” [al-Insaan 76:7] al-Tabaraani reported
    with a saheeh isnaad that Qutaadah said: “They used to vow to do acts of worship such
    as praying, fasting, giving zakaat and going on pilgrimage (Hajj and ‘Umrah), and
    other acts which were obligatory for them, and so Allaah called them abraar (those
    who are pious, fear Allaah, and avoid evil – see al-Insaan 76:5). It is clear
    that it is not those who make vows of repayment (nadhr al-mujaazaah) who are
    praised…”
Al-Baydaawi said: “People usually make vows conditional upon gaining
    some benefit or removing some evil, and this is forbidden because it is the way of the
    miser. If a generous person wants to draw closer to Allaah, he starts doing good deeds
    straight away, but the miser would never voluntarily give anything except in return for
    something which he is given first. This attitude will not protect him from anything that
    has already been decreed, or bring him any good thing that has not been decreed for him.
    The vow will be in accordance with qadar and will make him give something that he would
    not have given otherwise… And Allaah knows best.”