(3) باب الاِجْتِهَادِ فِي الْعَشْرِ الأَوَاخِرِ مِنْ شَهْرِ رَمَضَانَ
'A'isha (Allah be pleased with her) reported that when the last ten nights began Allah's Messenger (ﷺ) kept awake at night (for prayer and devotion), wakened his family, and prepared himself to observe prayer (with more vigour).
Reference: Sahih Muslim 1174
In-book reference: Book 14, Hadith 8
USC-MSA web (English) reference(deprecated numbering scheme): Book 6, Hadith 2643