(178) باب الرَّجُلِ يُصَلِّي مُخْتَصِرًا
Abu hurairah said that the Messenger of Allah (May peace be upon him) forbade putting hands on the waist during prayer.Abu Dawud said; The word Ikhtisar means to put one's hands on one's waist.
Reference: Sunan Abi Dawud 947
In-book reference: Book 2, Hadith 558
English translation: Book 2, Hadith 947