Sahih al-Bukhari 3458
Book 60: Prophets · Narrated by `Aisha
Arabic
حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، حَدَّثَنَا سُفْيَانُ، عَنِ الأَعْمَشِ، عَنْ أَبِي الضُّحَى، عَنْ مَسْرُوقٍ، عَنْ عَائِشَةَ ـ رضى الله عنها كَانَتْ تَكْرَهُ أَنْ يَجْعَلَ {الْمُصَلِّي} يَدَهُ فِي خَاصِرَتِهِ وَتَقُولُ إِنَّ الْيَهُودَ تَفْعَلُهُ. تَابَعَهُ شُعْبَةُ عَنِ الأَعْمَشِ.
English translation
Narrated `Aisha:That she used to hate that one should keep his hands on his flanks while praying. She said that the Jews used to do so
Reference: Sahih al-Bukhari 3458, Book of Prophets. English translation by Dr. Muhammad Muhsin Khan.