Since returning one’s greeting involves mentioning Allah, this mentioning has to be voided while answering the call of nature. Abdullah ibn Omar narrated that a man passed by and greeted the Prophet (ﷺ) while he was urinating, but the Prophet (ﷺ) did not return his greeting. It was as if he disliked mentioning Allah in that state of exposed private parts and lack of purity. In Sunan Abu Daoud, Al-Muhajer ibn Qunfudh narrated, "He came to the Prophet (ﷺ) while he was urinating. He greeted him but the Prophet did not return his greeting until he performed ablution. He then apologized to him and said, "I disliked mentioning Allah, the Almighty, except in the state of purification." This is evidence that the word "salam" (peace) that people use in greeting one another is one of Allah's names. Finally, this hadith contains the following benefits: (1) It urges Muslims to maintain their purity while mentioning Allah which has a high virtue, and (2) It confirms that it is better to refrain from mentioning Allah while being in inappropriate states like urinating and the like..