It was narrated from Ka’b bin ‘Ujrah that the Messenger of Allah ﷺ saw a man who had interlocked his fingers during the prayer, so the Messenger of Allah ﷺ separated his fingers.
أَنَّ رَسُولَ اللَّهِ ﷺ رَأَى رَجُلاً قَدْ شَبَّكَ أَصَابِعَهُ فِي الصَّلاَةِ فَفَرَّجَ رَسُولُ اللَّهِ ﷺ بَيْنَ أَصَابِعِهِ