It is narrated from Sayyiduna Abu Qatadah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) forbade that "a person should breathe into a vessel, or touch his private part with his right hand, or perform istinja (cleaning after relieving oneself) with his right hand."
Hadith Referenceالفتح الربانی / كتاب الطهارة / 531
Hadith Gradingمحدثین:صحیح
Hadith Takhrij«أخرجه البخاري: 153، ومسلم: 267، (انظر مسند أحمد ترقيم الرسالة: 22522 ترقیم بيت الأفكار الدولية: 22889»
Brief Explanation
Benefits: … The jurisprudential ruling (fiqh) of this hadith is that, to the best of one’s ability, in every situation the right hand should be prevented from touching the private part, because during relieving oneself and performing istinja (cleansing after relieving oneself), there could be a need for the right hand. Nevertheless, even in such a case, it has been prohibited to do so.