Musnad Ahmad 821
It was narrated from ‘Amr bin Sulaim az-Zuraqi that his mother said:
We were in Mina and we heard someone shouting that the Messenger of Allah   (ﷺ) was saying: `Do not fast, for these are days of eating and drinking.” She said: I lifted the edge of the tent and saw that the one who was shouting was `Ali bin Abi Talib.
حَدَّثَنَا يَحْيَى بْنُ غَيْلَانَ، حَدَّثَنَا الْمُفَضَّلُ بْنُ فَضَالَةَ، حَدَّثَنِي يَزِيدُ بْنُ عَبْدِ اللَّهِ، عَنْ عَبْدِ اللَّهِ بْنِ أَبِي سَلَمَةَ، عَنْ عَمْرِو بْنِ سُلَيْمٍ الزُّرَقِيِّ، عَنْ أُمِّهِ، قَالَتْ كُنَّا بِمِنًى فَإِذَا صَائِحٌ يَصِيحُ أَلَا إِنَّ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ لَا تَصُومُنَّ فَإِنَّهَا أَيَّامُ أَكْلٍ وَشُرْبٍ قَالَتْ فَرَفَعْتُ أَطْنَابَ الْفُسْطَاطِ فَإِذَا الصَّائِحُ عَلِيُّ بْنُ أَبِي طَالِبٍ‏.‏