Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 761
Abu Qilaba reported that he saw Malik b. Huwairith raising his hands at the beginning of prayer and raising his hands before kneeling down, and raising his hands after lifting his head from the state of kneeling, and he narrated that the Messenger of Allah (may peace be upon him) used to do like this.