"The Messenger of Allah used to fast until we said: 'He does not want to break his fast.' And he used not to fast until we said: 'He does not want to fast."' (Using translation from Nasāʾī 2347)
كَانَ رَسُولُ اللهِ ﷺ يَصُومُ حَتَّى نَقُولَ مَا يُرِيدُ أَنْ يُفْطِرَ وَيُفْطِرُ حَتَّى نَقُولَ مَا يُرِيدُ أَنْ يَصُومَ وَكَانَ يَقْرَأُ فِي كُلِّ لَيْلَةٍ بَنِي إِسْرَائِيلَ وَالزُّمَرَ