Hadith 506520
Chapter 18: Fasting - كتاب الصيام
قَالَ يَحْيَى قَالَ مَالِكٌ قَالَ هِشَامُ بْنُ عُرْوَةَ قَالَ عُرْوَةُ بْنُ الزُّبَيْرِ لَمْ أَرَ الْقُبْلَةَ لِلصَّائِمِ تَدْعُو إِلَى خَيْرٍ .
Yahya said that Malik said that Hisham ibn Urwa ibn az-Zubayr had said, "I do not think that kissing invites to good for people who are fasting."
Reference Muwatta Malik 506520
USC-MSA web (English) reference : Book 18, Hadith 18