The priest does not wash his hands because they are dirty, but to signify a spiritual meaning.
When attending a Catholic Mass, you may notice that the priest washes his hands immediately before reciting the Eucharistic prayer at the altar.
At first glance it may seem as though the priest is washing his hands because of dirt, but if that were the only reason, why not wash his hands before Mass?
The reason is spiritual, as St. Cyril of Jerusalem notes in his Catechetical Lectures.
The priest says a quiet prayer at this point in the liturgy that reinforces this reality.
It is a simple gesture, but one that has profound spiritual meaning.
The ritual is meant to remind the priest that he is called to live purely and devoutly, avoiding all sin.
Everything in the liturgy has a meaning, though it may not be clearly evident.
