"Elisha son of Shaphat is here. He used to pour water on the hands of Elijah." 2Ki.3:11

Eating utensils such as knives and spoons were probably not used to eat with, so it was necessary to wash one's hands at the end of a meal. Usually a pitcher and basin were used for this. The hands were held over the basin while a servant poured the water on them. The water was caught and used for other purposes.

The expression "used to pour water on the hands" shows the Elisha performed the work of a servant for Elijah. He was his assistant as well as his disciple.