Mishkat
al-Masabih
مشكاة المصابيح
Oaths and Vows
كتاب الإيمان والنذور
Chapter 1b: Vows - Section 2
باب في النذور - الفصل الثاني
Mishkat al-Masabih 3436
Ibn ‘Abbas reported Allah's Messenger ﷺ as saying, “If anyone takes a vow but does not name it, its atonement is the same as that for an oath; if anyone takes a vow to do an act of disobedience, its atonement is the same as that for an oath; if anyone takes a vow he is unable to fulfil, its atonement is the same as that for an oath; but if anyone takes a vow he is able to fulfil, he must do so.” Abu Dawud and Ibn Majah transmitted it, but some traced it no farther back than Ibn ‘Abbas.
وَعَنِ ابْنِ عَبَّاسٍ أَنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «مَنْ نَذَرَ نَذْرًا لم يسمه فَكَفَّارَتُهُ كَفَّارَةُ يَمِينٍ. وَمَنْ نَذَرَ نَذْرًا لَا يُطِيقُهُ فَكَفَّارَتُهُ كَفَّارَةُ يَمِينٍ. وَمَنْ نَذَرَ نَذْرًا أَطَاقَهُ فَلْيَفِ بِهِ» . رَوَاهُ أَبُو دَاوُدَ وَابْنُ مَاجَه وَوَقفه بَعضهم على ابْن عَبَّاس
In-book reference: Mishkat al-Masabih Book 15 Chapter 1b Hadith 1