नान्नमद्यादेकवासाः न नग्नः स्नानमाचरेत् |
न मूत्रं पथि कुर्वीत न भस्मनि न गोव्रजे ||
- मनु स्मृति
One must cover both his upper and lower body while eating. One must not take bath entirely naked. One must not urinate by the side of a path, or over ashes, or in a cattle shed. It is obvious why one must not urinate by the side of the path. Ashes and Cow-dung (cow-urine) are known to have other good uses. It should not be contaminated by human urine.
- Manu Smriti