Hadith 506500
Chapter 18: Fasting - كتاب الصيام
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ زَيْدِ بْنِ أَسْلَمَ، أَنَّ أَبَا هُرَيْرَةَ، وَسَعْدَ بْنَ أَبِي وَقَّاصٍ، كَانَا يُرَخِّصَانِ فِي الْقُبْلَةِ لِلصَّائِمِ .
Yahya related to me from Malik from Zayd ibn Aslam that Abu Hurayra and Sad ibn Abi Waqqas used to say that someone who was fasting was allowed to kiss.
Reference Muwatta Malik 506500
USC-MSA web (English) reference : Book 18, Hadith 17