Muwatta Malik 645

وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ يَحْيَى بْنِ سَعِيدٍ، أَنَّ عَاتِكَةَ ابْنَةَ زَيْدِ بْنِ عَمْرِو بْنِ نُفَيْلٍ، - امْرَأَةَ عُمَرَ بْنِ الْخَطَّابِ - كَانَتْ تُقَبِّلُ رَأْسَ عُمَرَ بْنِ الْخَطَّابِ وَهُوَ صَائِمٌ فَلاَ يَنْهَاهَا ‏.‏

Yahya related to me from Malik from Yahya ibn Said that Atika bint Zayd ibn Amr ibn Nufayl, the wife of Umar ibn al-Khattab, used to kiss Umar ibn al-Khattab's head while he was fasting, and he did not tell her not to

Reference

Muwatta Malik 645

In-book

Book 18, Hadith 16