وَالْمَاسِحُ عَلَى الْخُفَّيْنِ الْغَاسِلِينَ.
Meaning: One who validly wipes over khuffs may lead those who have washed their feet.
Wiping over khuffs, under its conditions, is an authorized alternative to washing the feet. A validly purified imam may lead followers who used the normal method of washing.