Sharḥ Riyāḍ al-Ṣāliḥīn - Ibn al-'Uthaymin - (6/691)

are threatened with something dreadful—hypocrisy that Allah may lodge in your heart until the day you die. Allah the Exalted says:
“Among them are those who pledged to Allah, ‘If He grants us out of His bounty, we will certainly give in charity and will surely be among the righteous.’ Yet when He did give them of His bounty, they became stingy with it and turned away, reneging on their pledge. So He caused hypocrisy to settle in their hearts until the day they meet Him.” (Quran 9:75-77)

They had vowed to Allah, “If He grants us wealth, we will donate from it and stand firm in obeying Him.” But once He gave them what they wanted, they withheld it and turned their backs—failing to honor what they had pledged. Consequently, He placed in their hearts a lasting hypocrisy: they are never granted success to repent from it, it never departs from their hearts, but stays with them until they die—we seek refuge in Allah from hypocrisy.

Therefore, my Muslim brother, beware of making vows and warn your fellow Muslims. Tell the sick person, “If Allah wills your cure, He will heal you without any vow.” Tell the student, “If Allah wills your success, you will succeed without a vow.” Tell the one who has lost something, “If Allah wills, He will return it to you without a vow.” Be sincere with Allah within yourself; when your wish is fulfilled, then thank Him—give whatever charity you like, fast, pray. But do not make a vow, as though Allah will only grant you if you impose a condition upon Him—may Allah grant us well-being.

For this reason the opinion that vows are forbidden is a strong one, and it is the position toward which Shaykh al-Islam Ibn Taymiyyah (d. 728 AH) inclined.

As for someone who vows to disobey Allah, he must not do so. If he were to vow, for instance, to drink wine, drinking it remains forbidden; he is not allowed to say, “I have vowed, so I must fulfill my vow.” We reply, “There is no fulfilling a vow that involves disobedience to Allah.” If he vows to assault someone, it is unlawful for him to carry out that assault—even if he swore to do so

مهدد بأمر عظيم مهدد بنفاق يجعله الله في قلبك حتى تموت قال الله ﷿ ومنهم من عاهد الله لئن ءاتانا من فضله لنصدقن ولنكونن من الصالحين عاهدوا الله إن أعطانا مالا لنتصدق منه ونقوم بطاعة الله ﴿فلما ءاتاهم من فضله﴾ وتم لهم مطلوبهم ﴿بخلوا به وتولوا﴾ ما وفوا بما عاهدوا الله عليه ﴿فأعقبهم نفاقا في قلوبهم إلى يوم يلقونه﴾ نفاق دائم لا يوفقون إلى التوبة منه ولا تنسلخ قلوبهم منه بل يبقى في قلوبهم إلى أن يموتوا والعياذ بالله على النفاق فالمهم يا أخي المسلم احذر النذر وحذر إخوانك المسلمين وقل للمريض إن أراد الله لك شفاء شفاك بدون نذر وقل للتلميذ إن أراد الله أن تنجح نجحت بدون نذر وقل لمن ضاع منه شيء إن أراد الله آتاك به من غير نذر واصدق الله في نفسك إذا حصل ذلك الشيء فحينئذ أشكر الله تصدق بما شئت صم صل أما أن تنذر وكأن الله ﷿ لا يأتي إلا إذا شرط له شرط نسأل الله العافية ولهذا فالقول بالتحريم قول قوي وإليه مال شيخ الإسلام ابن تيمية ﵀ أما من نذر أن يعصى الله فلا يعصه ولو نذر أن يشرب الخمر مثلا حرم عليه شربها ولا يحل له أن يشرب الخمر بالنذر لا يقول أنا نذرت وأوفي بنذري نقول لا وفاء لنذر في معصية الله لو نذر أن يعتدي على شخص لا يحل أن يعتدي عليه ولو نذر لو