Note By starting with at least one revi'it per hand when washing, we avoid problems of transferring tum'a to other people or utensils. If you start with only one revi'it and pour enough to cover each hand from that single revi'it, you will remove the tum'a from your hands, but the water that remains on your hands will still be tamei. If you then touch a washing cup, the tamei water will remain on the cup and be transferred to the person who touches it next. It is recommended to use at least one revi'it per hand to avoid such problems.