"A rabbit that a man had grilled was brought to the Prophet and when he offered it to him he said: 'O Messenger of Allah, I saw some blood on it." The Messenger of Allah did not eat it, but he said to those who were with him: "Eat; if I felt like it, I would have eaten it.' There was a man sitting, and the Messenger of Allah said: 'Come and eat with the people.' He said: 'O Messenger of Allah, I am fasting.' He said: 'Why don't you fast Al-Bid?' He said: 'What are they?' He said: "The thirteenth, fourteenth and fifteenth?"' (Using translation from Nasāʾī 2429)  

أُتِيَ النَّبِيُّ ﷺ بِأَرْنَبٍ قَدْ شَوَاهَا رَجُلٌ فَلَمَّا قَدَّمَهَا إِلَيْهِ قَالَ يَا رَسُولَ اللهِ إِنِّي رَأَيْتُ بِهَا دَمًا فَتَرَكَهَا رَسُولُ اللهِ ﷺ فَلَمْ يَأْكُلْهَا وَقَالَ لِمَنْ عِنْدَهُ «كُلُوا فَإِنِّي لَوْ اشْتَهَيْتُهَا أَكَلْتُهَا» وَرَجُلٌ جَالِسٌ فَقَالَ رَسُولُ اللهِ ﷺ «ادْنُ فَكُلْ مَعَ الْقَوْمِ» فَقَالَ يَا رَسُولَ اللهِ إِنِّي صَائِمٌ قَالَ «فَهَلَّا صُمْتَ الْبِيضَ؟» قَالَ وَمَا هُنَّ؟ قَالَ «ثَلَاثَ عَشْرَةَ وَأَرْبَعَ عَشْرَةَ وَخَمْسَ عَشْرَةَ»  

"Umar, May Allah be pleased with us on the day when we stopped at Al-Qaha?' Abu Dharr said: 'I was. A rabbit was brought to the Messenger Allah and the man who brought it said: I saw it bleeding (menstruating). The Prophet did not eat, then he said: "Eat." A man said: "I am fasting." He said: "What fast are you observing?" He said: "Three days each month" He said: "Why don't yo0u fast the bright shining days, the thirteenth, fourteenth and fifteenth."' (Using translation from Nasāʾī 4311)  

قَالَ أَبُو ذَرٍّ أَنَا أُتِيَ النَّبِيُّ ﷺ بِأَرْنَبٍ فَقَالَ الرَّجُلُ الَّذِي جَاءَ بِهَا إِنِّي رَأَيْتُهَا تَدْمَى فَكَأَنَّ النَّبِيَّ ﷺ لَمْ يَأْكُلْ ثُمَّ إِنَّهُ قَالَ «كُلُوا» فَقَالَ رَجُلٌ إِنِّي صَائِمٌ قَالَ «وَمَا صَوْمُكَ؟» قَالَ مِنْ كُلِّ شَهْرٍ ثَلَاثَةُ أَيَّامٍ قَالَ «فَأَيْنَ أَنْتَ عَنِ الْبِيضِ الْغُرِّ ثَلَاثَ عَشْرَةَ وَأَرْبَعَ عَشْرَةَ وَخَمْسَ عَشْرَةَ؟»