Shama-il Tirmidhi Chapter 23, Hadith Number 1 (130).
Kaa’b bin Maalik Radiyallahu ‘Anhu says: “Rasulullah Sallallabu ‘Alayhi Wasallam licked his fingers thrice (after eating)”. Commentary.After eating it is mustahab to lick the fingers before washing the hands. According to some authorities, due to this narration it is mustahab…