It was narrated that Ibn 'Abbas said:

"A man came to him and said: 'I have made my wife forbidden to myself.' He said: 'You are lying, she is not forbidden to you.' Then he recited this Verse: 'O Prophet! Why do you forbid (for yourself) that which Allah has allowed to you.' (And he said): 'You have to offer the severest form of expiation: Freeing a slave.'"

أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ عَبْدِ الصَّمَدِ بْنِ عَلِيٍّ الْمَوْصِلِيُّ، قَالَ حَدَّثَنَا مَخْلَدٌ، عَنْ سُفْيَانَ، عَنْ سَالِمٍ، عَنْ سَعِيدِ بْنِ جُبَيْرٍ، عَنِ ابْنِ عَبَّاسٍ، قَالَ أَتَاهُ رَجُلٌ فَقَالَ إِنِّي جَعَلْتُ امْرَأَتِي عَلَىَّ حَرَامًا . قَالَ كَذَبْتَ لَيْسَتْ عَلَيْكَ بِحَرَامٍ ثُمَّ تَلاَ هَذِهِ الآيَةَ { يَا أَيُّهَا النَّبِيُّ لِمَ تُحَرِّمُ مَا أَحَلَّ اللَّهُ لَكَ } عَلَيْكَ أَغْلَظُ الْكَفَّارَةِ عِتْقُ رَقَبَةٍ .