Imam Hasan al-Basri (may Allah have mercy on him) said: Sayyiduna Ma'qil bin Yasar (may Allah be pleased with him) was eating food at noon when a morsel of his fell down. He cleaned off the dirt from it and then ate it. The farmers began signaling with their eyes. People said to him: Do you see what these non-Arabs are saying? They say, "Look at how much food is in front of him, yet he picks up and eats that morsel." Sayyiduna Ma'qil (may Allah be pleased with him) replied: I cannot abandon what I have heard just because of what these non-Arabs say. We were commanded that when a morsel falls from any of you, he should clean off whatever dirt (etc.) has stuck to it and then eat it.
Hadith Referenceسنن دارمي / من كتاب الاطعمة / 2068
Hadith Gradingتحقیق (حسین سلیم أسد الدارانی):إسناده ضعيف لانقطاعه: الحسن لم يسمع معقل بن يسار ولكن المرفوع منه صحيح يشهد له سابقه، [مكتبه الشامله نمبر: 2072]
Hadith Takhrijاس حدیث کی سند میں انقطاع ہے، کیونکہ حسن رحمہ اللہ نے سیدنا معقل رضی اللہ عنہ سے سنا ہی نہیں، لیکن رسول اللہ صلی اللہ علیہ وسلم کا فرمان مبارک صحیح سند سے موجود ہے جیسا کہ اوپر گذر چکا ہے۔ اس کا حوالہ دیکھئے: [ابن ماجه 3278] ، [طبراني 200/20، 450، 451]
Brief Explanation
(Commentary on Ahadith 2066 to 2068)
The meaning of Sayyiduna Ma'qil bin Yasar radi Allahu anhu was that I will not abandon (acting upon) the noble hadith, even if these non-Arab foreigners laugh at me, taunt me, or speak ill of me.
Subhan Allah! It is obligatory upon every believer to follow the noble hadith and the Sunnah in this very manner, even if the worldly people consider acting upon it to be bad, or they taunt and reproach, or are ready to cause harm, or consider (the follower) insignificant.
(Wahidi).
From this hadith, it is understood that if a morsel falls from someone's hand, he should clean off the dust and eat it, unless cleaning it is not possible.