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. (Using translation from Abū Dāʾūd 947)
نَهَى رَسُولُ اللهِ ﷺ عَنِ التَّخَصُّرِ فِي الصَّلَاةِ