It was narrated that 'Aishah said the Messenger of Allah (ﷺ) would come and say: "Do you have any food for breakfast?" and we would say no, so he would say: "I am fasting." One day he came to us and we had been given some Hais. He said: "Do you have anything (to eat)?" and we said: "Yes, we have been given some Hais." He said: "I started the day wanting to fast," but then he ate.
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ الْهَيْثَمِ، قَالَ حَدَّثَنَا أَبُو بَكْرٍ الْحَنَفِيُّ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ طَلْحَةَ بْنِ يَحْيَى، عَنْ مُجَاهِدٍ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَجِيءُ وَيَقُولُ " هَلْ عِنْدَكُمْ غَدَاءٌ " . فَنَقُولُ لاَ . فَيَقُولُ " إِنِّي صَائِمٌ " . فَأَتَانَا يَوْمًا وَقَدْ أُهْدِيَ لَنَا حَيْسٌ فَقَالَ " هَلْ عِنْدَكُمْ شَىْءٌ " . قُلْنَا نَعَمْ أُهْدِيَ لَنَا حَيْسٌ . قَالَ " أَمَا إِنِّي قَدْ أَصْبَحْتُ أُرِيدُ الصَّوْمَ " . فَأَكَلَ خَالَفَهُ قَاسِمُ بْنُ يَزِيدَ .
sunnah.com