Mishkat al-Masabih
Mishkat al-Masabih 331
Circumstances which make ablution necessary - Section 3
Arabic hadith text
وَعَن ابْن مَسْعُود كَانَ يَقُولُ: مِنْ قُبْلَةِ الرَّجُلِ امْرَأَتَهُ الْوُضُوءُ. رَوَاهُ مَالك
Translation
Ibn Mas'ud used to say, “Ablution is necessary when a man kisses his wife.” Malik transmitted it.