"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.'" (Using translation from Nasāʾī 3420)   

كَذَبْتَ لَيْسَتْ عَلَيْكَ بِحَرَامٍ ثُمَّ تَلَا هَذِهِ الْآيَةَ {يَا أَيُّهَا النَّبِيُّ لِمَ تُحَرِّمُ مَا أَحَلَّ اللهُ لَكَ} [التحريم 1] عَلَيْكَ غِلَظُ الْكَفَّارَةِ أَعْتِقْ رَقَبَةً