Sahih Bukhari
Prayer at Night (Tahajjud)
Volume: 002 / Book Number: 021 / Hadith Number: 227
Narrated 'Ali bin Abi Talib
One night Allah's Apostle came to me and Fatima, the daughter of the Prophet and asked, "Won't you pray (at night)?" I said, "O Allah's Apostle! Our souls are in the hands of Allah and if He wants us to get up He will make us get up." When I said that, he left us without saying anything and I heard that he was hitting his thigh and saying, "But man is more quarrelsome than anything." (18.54)