Sunan Sa'id

His (Allah's) saying: {O you who have believed, do not approach prayer while you are intoxicated until you know what you are saying, nor in a state of janabah except those passing through [a place of prayer], until you have washed [your whole body]. And if you are ill or on a journey or one of you comes from the place of relieving himself or you have contacted women and do not find water, then seek clean earth and wipe over your faces and your hands [with it]. Indeed, Allah is ever Pardoning and Forgiving}