Chapter on Etiquettes of Causes Requiring Purification

The Shaykh (Al-Mufid), may Allah سبحانه وتعالى support him, narrated to me from Ahmad bin Muhammad bin Al-Hasan, from his father, from Muhammad bin Yahya and Ahmad bin Idris together, from Muhammad bin Ahmad bin Yahya, from Ahmad bin Al-Hasan bin Faddal, from Amr bin Sa‘id, from Musaddiq bin Sadaqah, from Ammar bin Musa, from Abu Abdullah عليه السلام, in a lengthy narration, who said: (Narrator said) "If wind (gas) is expelled from a person, is it obligatory for him to perform istinja (cleansing)? Imam عليه السلام said: 'No.' And Imam عليه السلام said: 'If a man urinates and nothing else is discharged, then he is only required to wash his private part (urethra) and not his anus. However, if something is discharged from his anus and he does not urinate, then he is only required to wash his anus and not his private part (urethra).' And Imam عليه السلام said: 'It is only obligatory for him to wash what is apparent (external) and not what is internal.'"