Sheikh Fawzān (may Allāh preserve him) said, “The wisdom – and Allāh knows best – in these four parts of the body being specified in wuḍū` is that they are the first parts of the body move to commit sins, and purifying them outwardly reminds us to purify them inwardly. The Prophet (May Allāh praise him and Peace be upon him) said that whenever a Muslim washes one of these body parts, this removes every sin he committed with that part of the body and his sins leave him with the water or with the last drop of water.