Ablution is a prerequisite to the validity of prayer. A prayer is not accepted without ablution. However, performing ablution after relieving oneself is recommended. The Prophet (ﷺ) used to teach his nation the obligatory and recommended acts and did not always command them to perform recommended acts, but he may have sometimes abandoned them to confirm that it is legitimate to abandon them. In the past, people originally used to call the safe and spacious place in deserts in which they relieved themselves "gha'et." Afterward, they used this word to refer to excrement, for they hated to call it by its real name. In this hadith, Abdullah ibn Abbas narrated that when the Prophet (ﷺ) began to eat from a food provided to him after he came back from privy, his companions reminded him that he did not perform ablution after relieving himself. He answered in denial, “Why? Will I pray so I have to perform ablution?" He confirmed that it was not obligatory for a person to perform ablution after answering the call of nature. Finally, this hadith shows that it is only Islamic law that clarifies the cases in which the ablution is invalid or obligatory..