[Machine] He heard Talhah ibn Ubayd Allah say that a man came to the Messenger of Allah ﷺ and asked about Islam. The Messenger of Allah ﷺ replied, "There are five daily prayers during the day and night." The man asked if there was anything else besides them. The Messenger of Allah ﷺ replied, "No, unless you voluntarily offer extra prayers." This is narrated in Sahih al-Bukhari and Sahih Muslim in a hadith from Malik.  

أَنَّهُ سَمِعَ طَلْحَةَ بْنَ عُبَيْدِ اللهِ يَقُولُ جَاءَ رَجُلٌ إِلَى رَسُولِ اللهِ ﷺ فَإِذَا هُوَ يَسْأَلُ عَنِ الْإِسْلَامِ فَقَالَ رَسُولُ اللهِ ﷺ خَمْسُ صَلَوَاتٍ فِي الْيَوْمِ وَاللَّيْلَةِ فَقَالَ هَلْ عَلَيَّ غَيْرُهَا قَالَ لَا إِلَّا أَنْ تَطَوَّعَ مُخَرَّجٌ فِي الصَّحِيحَيْنِ مِنْ حَدِيثِ مَالِكٍ  

Ibn Muhayriz said: A man from Banu Kinanah, named al-Makhdaji, heard a person called AbuMuhammad in Syria, saying: The witr is a duty (wajib). Al-Makhdaji said: So I went to Ubadah ibn as-Samit and informed him. Ubadah said: AbuMuhammad told a lie. I heard the Messenger of Allah ﷺ say: There are five prayers which Allah has prescribed on His servants. If anyone offers them, not losing any of them, and not treating them lightly, Allah guarantees that He will admit him to Paradise. If anyone does not offer them, Allah does not take any responsibility for such a person. He may either punish him or admit him to Paradise. (Using translation from Abū Dāʾūd 1420)   

سَمِعَ سَمِعَ رَجُلًا بِالشَّامِ يُدْعَى أَبَا مُحَمَّدٍ يَقُولُ إِنَّ الْوِتْرَ وَاجِبٌ قَالَ الْمُخْدَجِيُّ فَرُحْتُ إِلَى عُبَادَةَ بْنِ الصَّامِتِ فَاعْتَرَضْتُ لَهُ وَهُوَ رَائِحٌ إِلَى الْمَسْجِدِ فَأَخْبَرْتُهُ بِالَّذِي قَالَ أَبُو مُحَمَّدٍ فَقَالَ عُبَادَةُ كَذِبَ أَبُو مُحَمَّدٍ سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ خَمْسُ صَلَوَاتٍ كَتَبَهُنَّ اللهُ عَلَى الْعِبَادِ فَمَنْ جَاءَ بِهِنَّ لَمْ يُضَيِّعْ مِنْهُنَّ شَيْئًا اسْتِخْفَافًا بِحَقِّهِنَّ كَانَ لَهُ عِنْدَ اللهِ عَهْدٌ أَنْ يُدْخِلَهُ الْجَنَّةَ وَمَنْ لَمْ يَأْتِ بِهِنَّ فَلَيْسَ لَهُ عِنْدَ اللهِ عَهْدٌ إِنْ شَاءَ عَذَّبَهُ وَإِنَّ شَاءَ أَدْخَلَهُ الْجَنَّةَ  

[Machine] Witr is not obligatory, but it is a sunnah established by the Messenger of Allah ﷺ. This is the statement of Ubada ibn as-Samit and ibn Abbas, and all of that is in addition to the other narrations mentioned regarding its place under the section of voluntary prayers.  

الْوِتْرُ لَيْسَ بِحَتْمٍ وَلَكِنَّهُ سُنَّةٌ سَنَّهَا رَسُولُ اللهِ ﷺ وَهُوَ قَوْلُ عُبَادَةَ بْنِ الصَّامِتِ وَابْنِ عَبَّاسٍ وَكُلُّ ذَلِكَ مَعَ سَائِرِ الْآثَارِ الْوَارِدَةِ فِيهِ مَوْضِعُهَا بَابُ صَلَاةِ التَّطَوُّعِ