Muwatta Imam Malik Book of Purity, Hadith 68

Yahya related to me from Malik that Ibn Shihab used to say, "Wudu is necessary if a man kisses his wife." Nafi said that Malik said, "That is what I like most out of what I have heard."

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، أَنَّهُ كَانَ يَقُولُ مِنْ قُبْلَةِ الرَّجُلِ امْرَأَتَهُ الْوُضُوءُ . قَالَ { ابْنُ } نَافِعٍ قَالَ مَالِكٌ وَذَلِكَ أَحَبُّ مَا سَمِعْتُ إِلَىَّ .