Sahih al-Bukhari 4911
Sahih al-Bukhari · Book 65: Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh)) · "O Prophet! Why do you forbid (for yourself) that which Allah has allowed to you?..." (V.66:1)
Narrated Ibn `Abbas:
حَدَّثَنَا مُعَاذُ بْنُ فَضَالَةَ ، حَدَّثَنَا هِشَامٌ ، عَنْ يَحْيَى ، عَنِ ابْنِ حَكِيمٍ ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ ، أَنَّ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ فِي الْحَرَامِ يُكَفِّرُ. وَقَالَ ابْنُ عَبَّاسٍ {لَقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ إِسْوَةٌ حَسَنَةٌ} .
If someone says to his wife, "You are unlawful to me." he must make an expiation (for his oath). Ibn `Abbas added: There is for you in Allah's Messenger (ﷺ), an excellent example to follow.