General Behavior (Kitab Al-Adab)
Dawud :: Book 41 : Hadith 5203
Narrated Al-Bara' ibn Azib:
I went in with AbuBakr when he had newly come to Medina and he found his daughter Aisha lying down afflicted with fever. AbuBakr went to her, and saying: How are you, girlie? kissed her on the cheek.