'A'isha reported that when the Messenger of Allah ﷺ stood up at night to pray, he began his prayer with two short rak'ahs. (Using translation from Muslim 767)   

كَانَ رَسُولُ اللهِ ﷺ إِذَا قَامَ مِنَ اللَّيْلِ لِيُصَلِّيَ افْتَتَحَ صَلَاتَهُ بِرَكْعَتَيْنِ خَفِيفَتَيْنِ  

[Machine] "On the authority of the Prophet ﷺ, he said: When one of you gets up in the night to pray, let him start his prayer with two light units (rak'ahs)."  

عَنِ النَّبِيِّ ﷺ قَالَ إِذَا قَامَ أَحَدُكُمْ مِنَ اللَّيْلِ فَلْيَفْتَتِحْ صَلَاتَهُ بِرَكْعَتَيْنِ خَفِيفَتَيْنِ  

[Machine] "The Prophet ﷺ used to begin his night prayer with two light rak'ahs, as narrated by a group of narrators including Hisham, who heard it directly from Abu Hurairah, among them Hammam bin Salamah and Hammam bin Zaid."  

أَنَّ النَّبِيَّ ﷺ كَانَ يَفْتَتِحُ صَلَاتَهُ مِنَ اللَّيْلِ بِرَكْعَتَيْنِ خَفِيفَتَيْنِ وَرَوَاهُ جَمَاعَةٌ عَنْ هِشَامٍ مَوْقُوفًا عَلَى أَبِي هُرَيْرَةَ مِنْهُمْ حَمَّادُ بْنُ سَلَمَةَ وَحَمَّادُ بْنُ زَيْدٍ وَكَذَلِكَ