Ibn ‘Abbas said:One makes atonement for something he has made unlawful for himself.* You have had a good example in God’s Messenger. * i.e. something not in itself unlawful. It is treated like an oath for breaking which atonement must be made. The Prophet’s example refers to his withdrawing from his wives for a period. (Bukhari and Muslim.)
Hadith Referenceمشكوة المصابيح / كتاب النكاح / 3277
Hadith Gradingالألبانی:مُتَّفَقٌ عَلَيْهِ | زبیر علی زئی:متفق عليه
Hadith Takhrij´تحقيق و تخريج: محدث العصر حافظ زبير على زئي رحمه الله` «متفق عليه، رواه البخاري (4911) و مسلم (1473/18)»