Sunan Abi Dawud 947
سنن أبي داود#947Sahihحَدَّثَنَا يَعْقُوبُ بْنُ كَعْبٍ، حَدَّثَنَا مُحَمَّدُ بْنُ سَلَمَةَ، عَنْ هِشَامٍ، عَنْ مُحَمَّدٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ نَهَى رَسُولُ اللَّهِ صلى الله عليه وسلم عَنْ الاِخْتِصَارِ فِي الصَّلاَةِ . قَالَ أَبُو دَاوُدَ يَعْنِي يَضَعُ يَدَهُ عَلَى خَاصِرَتِهِ .
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
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Al-AlbaniSahih
Muhammad Muhyi Al-Din Abdul HamidSahih
Shuaib Al ArnautSahih
Zubair Ali ZaiSahih Bukhari (1220) Sahih Muslim (545)
In-book reference: 2:558