Yahya related to me from Malik that Ibn Shihab used to say, "Wuduis necessary if a man kisses his wife." Nafi said that Malik said,"That is what I like most out of what I have heard." (DE)
USC-MSA web (English) reference: Book 2, Hadith 68 (DE)
Arabic reference (DE): Book 2, Hadith 98 (DE)