It is narrated from Sayyiduna Salman Farsi (may Allah be pleased with him), he says: I read in the Torah that washing hands after eating is a source of blessing. I mentioned this to the Noble Prophet (peace and blessings be upon him) and informed him of what I had read in the Torah. The Prophet (peace and blessings be upon him) said: The blessing of food is that ablution is performed before it and also after it.
Hadith Referenceالفتح الربانی / كتاب الأطعمة / 7378
Hadith Gradingمحدثین:ضعیف
Hadith Takhrij«اسناده ضعيف من اجل قيس بن الربيع، أخرجه ابوداود: 3761، والترمذي: 1846، (انظر مسند أحمد ترقيم الرسالة: 23732 ترقیم بيت الأفكار الدولية: 24133»
Brief Explanation
Benefits: … It is possible that the ablution (wudu) referred to here is the linguistic ablution, meaning washing the hands and face, so that the effects of oiliness and the like are removed.