‘Ā'ishah used to hate that one keeps his hands on his flanks (while praying). She said that the Jew used to do so
Authentic hadithعن عائشة رضي الله عنها أنها كانت تكره أن يجعل يده في خَاصِرَتِهِ، وتقول: إن اليهود تفعله.
It was reported that ‘Ā'ishah (may Allah be pleased with her) used to hate that one keeps his hands on his flanks (while praying). She said that the Jew used to do so.
Explanation
The noble Hadīth indicates that ‘Ā'ishah (may Allah be pleased with her) used to hate for a praying person to place his hand on his waist while praying. She explained the reason behind this by saying that it belongs to the actions of the Jews.
Source · Narrated by Bukhari
From the Hadith Encyclopedia (hadeethenc.com).