Hisham bin Urwah narrates from his father that Sayyiduna Umar al-Faruq (may Allah be pleased with him) went to relieve himself. When he came out after finishing, food was presented to him, and someone said to him: "Will you not perform ablution (before eating)?" He replied: "I purify myself (by istinja) with my left hand and I eat with my right hand."
The chain of this report is sahih (authentic), and Imam al-Humaydi narrated it in his Musnad. From it the juristic point becomes clear that after relieving oneself, performing the ritual ablution merely for the sake of eating is not obligatory; rather, cleanliness of the hands is sufficient.
Hadith Referenceالمطالب العالية بزوائد المسانيد الثمانية / كتاب الأطعمة والأشربة / 2405
Hadith Gradingمحدثین:إسناده صحيح، مرسل
Hadith Takhrij«حکم الحدیث المطالب العالیہ محققاً تنسیق د. سعد بن ناصر بن عبد العزيز الشَّثري- مکتبہ شاملہ :مرسل، إسناده صحيح. » «أخرجه مسند الحميدي برقم: 485، وأخرجه مصنف ابن أبي شيبة برقم: 1627»