Muwatta Malik 97
Purity
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، أَنَّهُ كَانَ يَقُولُ مِنْ قُبْلَةِ الرَّجُلِ امْرَأَتَهُ الْوُضُوءُ . قَالَ { ابْنُ } نَافِعٍ قَالَ مَالِكٌ وَذَلِكَ أَحَبُّ مَا سَمِعْتُ إِلَىَّ .
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
Grading: Salim al-Hilali: Maqtu Sahih
Text from the public-domain hadith-api dataset. Numbering follows that dataset and can differ by a few from some printed editions — check the wording, not only the number.