Shama-il Tirmidhi Chapter 53, Hadith Number 6 (373).
Ibn ‘Abbaas Radiyallahu ‘Anhu and ‘Aayeshah Radiyallahu ‘Anha report: “After the death of Rasulullah Sallallahu ‘Alayhi Wasallam, Abubakr Siddiqe Radiyallahu ‘Anhu came and kissed the forehead of Rasuluilah Sallallahu ‘Alayhi Wasallam”.
This hadith is mentioned in brief. A more detailed one will be mentioned later. This kissing of Sayyidina Rasulullah Sallallahu’Alayhi Wasallam as mentioned by the commentators are for barakah. According to this humble servant it was a farewell kiss, as it was the final parting of a beloved friend.