كتاب الصيام
13  
The Book of Fasting
(12)
Chapter: Clarifying that Kissing when fasting is not unlawful for the one whose desire is not provoked by that
(12)
باب بَيَانِ أَنَّ الْقُبْلَةَ فِي الصَّوْمِ لَيْسَتْ مُحَرَّمَةً عَلَى مَنْ لَمْ تُحَرِّكْ شَهْوَتَهُ ‏‏
Sahih Muslim 1106 g

Aswad reported:

I and Masruq went to 'A'isha (Allah be pleased with her) and asked. her if the Messenger of Allah (ﷺ) embraced (his wives) while fasting. She said: Yes; but he had the greatest control over his desire among you: or he was one of those who had control over his desire.
وَحَدَّثَنَا مُحَمَّدُ بْنُ الْمُثَنَّى، حَدَّثَنَا أَبُو عَاصِمٍ، قَالَ سَمِعْتُ ابْنَ عَوْنٍ، عَنْ إِبْرَاهِيمَ، عَنِ الأَسْوَدِ، قَالَ انْطَلَقْتُ أَنَا وَمَسْرُوقٌ، إِلَى عَائِشَةَ - رضى الله عنها - فَقُلْنَا لَهَا أَكَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُبَاشِرُ وَهُوَ صَائِمٌ قَالَتْ نَعَمْ وَلَكِنَّهُ كَانَ أَمْلَكَكُمْ لإِرْبِهِ أَوْ مِنْ أَمْلَكِكُمْ لإِرْبِهِ ‏.‏ شَكَّ أَبُو عَاصِمٍ ‏.‏
Reference : Sahih Muslim 1106g
In-book reference : Book 13, Hadith 85
USC-MSA web (English) reference : Book 6, Hadith 2442
  (deprecated numbering scheme)