كتاب الطهارة
2  
Purity

Yahya related to me from Malik from Ibn Shihab from Salim ibn Abdullah that his father Abdullah ibn Umar used to say, "A man's kissing his wife and fondling her with his hands are part of intercourse. Someone who kisses his wife or fondles her with his hand must do wudu."

حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنِ ابْنِ شِهَابٍ، عَنْ سَالِمِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِيهِ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ كَانَ يَقُولُ قُبْلَةُ الرَّجُلِ امْرَأَتَهُ وَجَسُّهَا بِيَدِهِ مِنَ الْمُلاَمَسَةِ فَمَنْ قَبَّلَ امْرَأَتَهُ أَوْ جَسَّهَا بِيَدِهِ فَعَلَيْهِ الْوُضُوءُ ‏.‏
USC-MSA web (English) reference : Book 2, Hadith 66
Arabic reference : Book 2, Hadith 96