It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him): "Whoever's hand touches his private part, let him perform ablution." This narration is mawquf. It is also said that Jamil narrates it from Abu Wahb, and he from Sayyiduna Abu Hurayrah (may Allah be pleased with him).
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 642
Hadith Gradingمحدثین:ضعيف
Hadith Takhrij«ضعيف۔ أخرجه البخاري التاريخ الكبير 2/216»