Sayyiduna Abu Qatadah (may Allah be pleased with him) narrated that he heard the Prophet Muhammad (peace and blessings be upon him) say: "When any one of you urinates, he should not hold his private part with his right hand, nor should he clean himself with his right hand, and he should not breathe into the vessel."
Hadith Referenceسنن دارمي / من كتاب الاشربة / 2159
Hadith Takhrijاس روایت کی سند صحیح اور حدیث متفق علیہ ہے۔ دیکھئے: [بخاري 153، 154] ، [مسلم 267] ، [أبوداؤد 31] ، [ترمذي 15] ، [نسائي 24] ، [ابن ماجه 310] ، [ابن حبان 1434] ، [الحميدي 432، وغيرهم]
Brief Explanation
(Commentary on Hadith 2158)
Three things are understood from this hadith: It is not permissible to touch the private part with the right hand, nor is it correct to perform istinja (cleansing after relieving oneself) with the right hand, and nor is it proper to breathe into a vessel. All these matters are contrary to the etiquettes of purification (taharah). The right hand is for good things and for eating and drinking, and the left hand is for purification.