"The Messenger of Allah came to me one day and said: 'Do you have anything (to eat) we said: 'No.' he said: 'Then I am fasting." (Using translation from Nasāʾī 2327)
دَخَلَ عَلَيَّ النَّبِيُّ ﷺ ذَاتَ يَوْمٍ فَقَالَ «هَلْ عِنْدَكُمْ شَيءٌ؟» قُلْنَا لَا قَالَ «فَإِنِّي صَائِمٌ»