It wasnarrated that Mus'ab bin Sa'd said:
"I bowed (in prayer)besidemy father, and I put my hands between my knees. He struck myhand andsaid: 'We used to do that, then we were commanded to put themonthe knees.'"
English reference: Vol. 1, Book 5, Hadith 873
Arabic reference: Book 5, Hadith 922