CHECK: Is it permissible to fold the bottom of the trousers during Salah?
it is sunnah to keep the bottom part of the trousers above the ankles. Keeping them below the ankles, without the intention of pride and arrogance, is Makruh [Tanzihi]. Having pride whilst doing so makes it Haram.
In relation to Namaz, it is Makruh-e-Tahrimi to fold any sewn garment. Any Namaz/Salaah performed whilst a Makruh-e-Tahrimi act had been committed has to be repeated again.
Therefore, one should NOT fold the trousers from below [which will be Makruh-e-Tahrimi and hence Salaah has to be repeated] but leave them unfolded [as in this case it will be Makruh-e-Tanzihi. however, Salaah shall still be valid]
It is advised that one keeps their trousers, jeans etc above their ankles so as to emulate the Sunnah of the Noble Messenger SallALLAHU ‘alayhi wa Sallam and hence reap immense reward
and Allah Knows best.