If someone says to his wife, "You are unlawful to me." he must make an expiation (for his oath). Ibn ʿAbbas added: There is for you in Messenger of Allah ﷺ, an excellent example to follow.  

وَقَالَ ابْنُ عَبَّاسٍ {لَقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ إِسْوَةٌ حَسَنَةٌ}  

that he heard Ibn ʿAbbas saying, "If a man makes his wife unlawful for him, it does not mean that she is divorced." He added, "Indeed in the Messenger of Allah , you have a good example to follow."  

وَقَالَ {لَقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ أُسْوَةٌ حَسَنَةٌ}  

Verily, there is in the Messenger of Allah ﷺ a model pattern for you.  

أَنَّهُ كَانَ يَقُولُ فِي الْحَرَامِ يَمِينٌ يُكَفِّرُهَا وَقَالَ ابْنُ عَبَّاسٍ { لَقَدْ كَانَ لَكُمْ فِي رَسُولِ اللَّهِ أُسْوَةٌ حَسَنَةٌ}