Mishkat al-Masabih

Jabir said the Prophet (ﷺ) ordered people to lick their fingers and the dish, saying, “You do not know in what portion blessing lies.” Muslim transmitted it.

وَعَنْ جَابِرٌ: أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ أَمَرَ بِلَعْقِ الْأَصَابِعِ وَالصَّفْحَةِ وَقَالَ: " إِنَّكُمْ لَا تَدْرُونَ: فِي أَيَّهِ الْبَرَكَةُ؟ ". رَوَاهُ مُسْلِمٌ