عَنْ جَابِرٍ رَضِيَ اللَّهُ عَنْهُ قَالَ قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ إِذَا أَكَلَ أَحَدُكُمْ طَعَامًا فَلَا يَمْسَحْ يَدَهُ فِي الْمِنْدِيلِ حَتَّى يَلْعَقَهَا أَوْ يُلْعِقَهَا فَإِنَّهُ لَا يَدْرِي فِي أَيِّ طَعَامِهِ الْبَرَكَةُ وَفِي لَفْظٍ فَلَا يَمْسَحْ يَدَهُ حَتَّى يَمُصَّهَا فَإِنَّهُ لَا يَدْرِي فِي أَيِّ طَعَامٍ يُبَارَكُ لَهُ فِيهِ
Sayyiduna Jabir (may Allah be pleased with him) narrates that the Noble Prophet (peace and blessings be upon him) said: When any of you finishes eating food, he should not wipe his hands with a cloth until he has licked them or had them licked, because he does not know in which part of the food the blessing lies. In another narration, the words are: He should not clean his hands until he has sucked them, because he does not know in which part of the food blessing has been placed for him.