A man from the Companions of the Prophet ﷺ told me that the Messenger of Allah ﷺ prohibited cupping and perpetual fasting, but he had not made them unlawful showing mercy on his Companions. Thereupon he was asked: Messenger of Allah, you observe perpetual fast till dawn. He replied: I observe perpetual fast till dawn (for) my Lord gives me food and drink. (Using translation from Abū Dāʾūd 2374)
حَدَّثَنِي رَجُلٌ مِنْ أَصْحَابِ النَّبِيِّ ﷺ أَنَّ رَسُولَ اللهِ ﷺ نَهَى عَنِ الْحِجَامَةِ وَالْمُوَاصَلَةِ وَلَمْ يُحَرِّمْهَا إِبْقَاءً عَلَى أَصْحَابِهِ فَقِيلَ يَا رَسُولَ اللهِ إِنَّكَ تُوَاصِلُ إِلَى السَّحَرِ فَقَالَ إِنْ أُوَاصِلُ إِلَى السَّحَرِ فَرَبِّي يُطْعِمُنِي وَيَسْقِينِي