مُوَطَّأُ مَالِكٍ
Muwatta Malik 652
Fasting
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."
Arabic/English book reference: Book 18, Hadith 18