It is prohibited to wear pants below the ankle at all times. Rasulullah (Sallallaahu Alayhi Wasallam) said, ?Allah will not look at a person with mercy who lowers his pants below his ankle.? (Bukhari)
To perform Salaat with the pants below the ankles is Makrooh. Therefore, the pants should be folded above the ankles at all times, in particular, during Salaat.
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai