The Book of Funerals
21/11. Chapter:
Kissing the Deceased
Sunan an-Nasai
أَخْبَرَنَا أَحْمَدُ بْنُ عَمْرٍو، قَالَ أَنْبَأَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، أَنَّ أَبَا بَكْرٍ، قَبَّلَ بَيْنَ عَيْنَىِ النَّبِيِّ صلى الله عليه وسلم وَهُوَ مَيِّتٌ .
It was narrated from 'Aishah: that Abu Bakr kissed the Prophet between the eyes when he had died.
Reference : Sunan an-Nasa'i 1839In-book reference : Book 21, Hadith 22English translation : Vol. 3, Book 21, Hadith 1840