Anas bin Sirin reported,

I asked Ibn Umar, "What is your view on the two units of prayer before the dawn prayer? Should I lengthen the recitation in them?"He replied, "The Messenger of Allah ﷺ used to pray during the night in pairs and would conclude with a single witr unit."I said, "This is not what I am asking you about."He said, "You are dense! Will you not let me relate the hadith to you in full? The Messenger of Allah ﷺ used to pray during the night in pairs and would conclude with a single witr unit, then he would pray two units before the dawn prayer as though the call to prayer were ringing in his ears."Khalaf said, "What is your view on the two units before the dawn?" without mentioning the word "prayer."

Muslim 1761

Sahih

حدثنا خلف بن هشام وأبو كامل قالا حدثنا حماد بن زيد

عن أنس بن سيرين قال

سألت ابن عمر قلت أرأيت الركعتين قبل صلاة الغداة أؤطيل فيهما القراءة قال كان رسول الله ﷺ يصلي من الليل مثنى مثنى ويوتر بركعة قال قلت إني لست عن هذا أسألك قال إنك لضخم ألا تدعني أستقرئ لك الحديث كان رسول الله ﷺ يصلي من الليل مثنى مثنى ويوتر بركعة ويصلي ركعتين قبل الغداة كأن الأذان بأذنيه قال خلف أرأيت الركعتين قبل الغداة ولم يذكر صلاة

مسلم 1761صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Muslim
Book
Travelers' prayer and its shortening
Chapter
Night prayer is two rakats at a time and Witr is one rakat at the end of the night
Numbering
Darussalam 1761
Muslim 1761