It wasnarrated from Ka'b bin 'Ujrah that the Messenger of Allah(ﷺ)saw a man who had interlocked his fingers during the prayer, sotheMessenger of Allah (ﷺ) separated his fingers. (JA)
English reference (JA): Vol. 1, Book 5, Hadith 967 (JA)
Arabic reference (JA): Book 5, Hadith 1020 (JA)