The Laws of Arising in the Morning (14)

1. Seeing that the evil spirit which rests on one’s hands passes on to the water from the hand-washing, it is forbidden to wash one’s hands on the floor. Instead, one should wash into a vessel. (Shulchan Aruch and Mishne Berura 4)

2. One should pour out this water in a place where people not pass. It is also forbidden to benefit from them, or even to give them to animals, for the evil spirit can damage them. (Mishne Berura ibid)