[Machine] The Prophet ﷺ was specifically ordered to observe the night prayer and was devoted to it.  

لِلنَّبِيِّ ﷺ خَاصَّةً أُمِرَ بِقِيَامِ اللَّيْلِ وَلَبِثَ عَلَيْهِ  

[Machine] The Messenger of Allah ﷺ said, "There are three obligations upon me, which are Sunnah for you: Witr prayer, using toothstick (miswak), and standing (in prayer) during the night." Musa bin Abdullah Rahman said, "This hadith is very weak and it is not established in this chain of narration. And Allah knows best."  

قَالَ رَسُولُ اللهِ ﷺ ثَلَاثَةٌ عَلَيَّ فَرِيضَةٌ وَهِيَ لَكُمْ سُنَّةٌ الْوِتْرُ وَالسِّوَاكُ وَقِيَامُ اللَّيْلِ مُوسَى بْنُ عَبْدِ الرَّحْمَنِ هَذَا ضَعِيفٌ جِدًّا وَلَمْ يَثْبُتْ فِي هَذَا إِسْنَادٌ وَاللهُ أَعْلَمُ  

[Machine] The Prophet ﷺ used to pray until his feet or legs became swollen. They said to him, "Why do you do this when Allah has forgiven you for all your sins?" He replied, "Shouldn't I be a thankful servant?"  

كَانَ رَسُولُ اللهِ ﷺ يُصَلِّي حَتَّى تَرِمَ أَوْ تَنْتَفِخَ رِجْلَاهُ أَوْ قَدَمَاهُ قَالَ فَقَالُوا لَهُ قَالَ أَفَلَا أَكُونُ عَبْدًا شَكُورًا؟  

Messenger of Allah you do this (in spite of the fact) that your earlier and later sins have been pardoned for you? Thereupon, he said. A'isha should I not prove myself to be a thanksgiving servant (of Allah)? (Using translation from Muslim 2820)   

رَسُولُ اللهِ ﷺ إِذَا صَلَّى قَامَ حَتَّى تَفْطُرَ رِجْلَاهُ فَقَالَتْ عَائِشَةُ ؓ يَا رَسُولَ اللهِ تَصْنَعُ هَذَا وَقَدْ غَفَرَ اللهُ لَكَ مَا تَقَدَّمَ مِنْ ذَنْبِكَ وَمَا تَأَخَّرَ؟ قَالَ يَا عَائِشَةُ أَفَلَا أَكُونُ عَبْدًا شَكُورًا؟