Abu Huraira reported Allah's Apostle ﷺ as saying When any one of you gets up at night, he should begin the prayer with two short rak'ahs. (Using translation from Muslim 768)
قَالَ رَسُولُ اللهِ ﷺ إِذَا قَامَ أَحَدُكُمْ مِنَ اللَّيْلِ فَلْيَسْتَفْتِحْ صَلَاتَهُ بِرَكْعَتَيْنِ خَفِيفَتَيْنِ